The Prius is an automatic. You cannot compare it against a more efficient manual drive. On a regular 300 mile drive to Devon via motorway and A-roads I get an average of 61mpg. Name me another automatic that can return that kind of efficiency?

Andrew, London, UK

The Ultra Low Sulfur Diesel In the US should cost no more than the old stuff. It's diesel prices trailing gas because of lower volume sales. You can blame GM for the diesel Olds in the late 70's for killing diesel here. There is no manual prius so I think its fair to compare to the automatic BMW.

Avery Nisbet, Sunnvale, USA

What you have to take into account is the lower tax based on co2 of 104g for the prius and also the great reimbursement rate for business mileage. Now thats economical on my pocket and it's a better car than the Audi A6 i previously owned. I'm also getting an average of 57mpg.

Graham, Glasgow, UK

In hot climates like the desert SW of the US, batteries have a shortened life span of 18 to 24 months. You would have to change out your $5K Prius battery pack every 2 years - more than an engine overhaul on a petrol or diesel car.

Diesel costs more in the US due to low sulfur reformulation.

Kris Staller, Tucson AZ, USA

What people are forgetting is this is not a fair test ok so the BMW 5 series is a bigger car.

The issue I have is that the 5 series is a manual the prius is automatic.

I think the test should be repeated with a 520d auto against the standard prius auto.

David Bergman, Manchester, UK

I feel sorry to all those that think (or even worse, OWN) the Prius. It has been proven time & time again that the Prius is in fact NOT economical in terms of the earth's resources or fuel. To have a comfy, safe, solid & far less embarrassing car for the same cost, im sold. I laugh when i c a Prius.

Tom Putney, Guildford, England

diesel is 10p a litre more so your figure should be £11.00 more for bema. i have done 115000mls in my prius in 3 years and is a fantastic car. all the petrol heads who test cars dont know the correct concept of the prius and dont drive it correctly i always get 55mpg at all speeds.

geoff, stevenage, uk

Hybrids con the rolling road tests using fuel stored as battery energy. Time for more realistic on road testing. Scrap the rolling road mpg and emission tests! Tax is at stake.

simon price, newport, Wales

I've no interest in a BMW but you're under-selling the Prius. Got my ex-demo Dec 07 with 670mls. Aug 08 I've 8150mls. MPG at first was ~ 54mpg (80/20 city/highway). Last six tanksful all just over 60mpg with same ratio. Motorways at 80 (ind) you'll get low 40s, at 70 ind it's 55. Ist class car.

Jim Simpson, Musselburgh, Scotland

You can't compare diesel and gasoline. Diesel has more than 15% as much energy per litre/gallon as gasoline. The BMW have to go 15 % longer on the amount of petrol.

Micke, Stockholm,

Why are you measuring fuel consumption in gpm, but filling up your cars in litres? Britain is weird.

Pontus, Stockholm, Sweden

I have just bought an 18 month old BMW 520d and have had markedly different results. Official combined mpg is 45 and yet I can't do better than 36 on a trip, and that is really trying hard. My previous Audi fared much better. Beware the differences between marques' published mpgs.

Steve, Kingston upon Thames, UK

A marvelous ad for the Prius!
In a test massively loaded to favour the BMW (4/5 open road,no checks on the accuracy of any of the measurements) the Prius loses by a mere few pence!
Try the same test without leaving the confines of Greater London and you'll feel like driving the BMW into the Thames!

Jack, Edmonton, Canada

Plants take in co2, and give off oxygen. It is a wonderful feedback system that uneducated people don't understand. Nature balances the 2 gases better than man ever could. This co2 mania is like the tulip craze in Holland, and just as contrived and false.

Michael, Evansville, usa

One notable thing: here in the states, diesel fuel runs about $.50-.75 more than gasoline. Any savings you got from buying one would be lost when you paid for your fuel, and then some.

David Nicholas, Montrose, CA, USA

I am seriously thinking of buying Prius, very soon as a company car. What is the response of the Toyota to this article?

R Sanikop, swansea,

1 liter of diesel gives more CO2 than 1 liter of petrol.

John, Oslo, Norway

This shows that hybrid technology is not the future!

S.Bey, Lahore, Pakistan

This is a test. Its a real world test, not a simulated or lab test- congrats BMW.

Damien O'Brien, Maidstone, England

So, even things out at the Prius is only about as economical as a BMW diesel. Now, how good for the environment are the batteries in the Prius?

If you've bought one because you think it's green, you're a fool.

Joe Santos, Cambridge, UK

Prius bitterness already - someone will no doubt cry foul claiming Jasons weighed more than toyota.

BMW wins - Prius is for losers...........get over it ! LOL

kevin, chichester, sussex

I bought a Prius in Aug '06. The 1st 5000 miles I averaged 55mpg. The next 5000 miles I averaged 60mpg. I am now averaging 65mpg. Getting the best out of a Prius or any other car is a question of driving style, a very light touch on the accelerator is all it needs. At £5/gallon this makes sense.

M F Radcliffe, Ashbourne, Derbyshire

This is not a test, this is a tabloid article, nothing more. The test setup and test conditions are not equal. Do the same test with 2 other persons and the results would be significantly different.

Jan De Ceuster, Turnhout, Belgium

Caluclated toward energy instead of volumes:

Prius : 11.34 x 32MJ/l = 390.24 MJ
BMW : 10.84 x 36MJ/l = 362.88 MJ

BMW consumed about 7.5% MORE!

Jan De Ceuster, Turnhout, Belgium

I drive a Prius and regularly average 50mpg in a combination of city and highway driving. If the diesels are better for highway driving, and that's what you do most, get a diesel. If you do more city driving, get a Prius. The Prius was available where I live and matches my driving needs.

Susie, Hawaii,

Sorry to spoil the fun, guys, but when comparing mpg figures, you can't assume that the car's trip computer is accurate. Many exaggerate fuel economy by 5-10%. The only way to find the truth is to calibrate the computer figures against actual mileage over several fillups. Did the testers do this?

Alasdair Beal, Leeds, UK

Put the same figures in now for Petrol and Diesel in the UK and the Prius wins by quite a margin, amazing what a difference a few months make and government dabbling.
It looks like this gap is set to get bigger.

Ray Page, Grays, uk

Simple thermodynamics makes it clear that the Prius is inherently inefficient. Yet thousands of uneducated motorists have wholeheartedly invested themselves in the Prius both emotionally and psychologically in order to assuage their personal "pollution-guilt". Heaven forbid BMW prove them wrong.

Steve, San Diego, USA

Its interesting to see that all the eco-mentalists think that a prius that not only has a 1.5l petrol engine but loads and loads of heavy batteries is somehow better than a car with a single engine. Also the whole life cost to the environment is much much higher with a prius.

ER, London,

If the chunky Englishman was driving his Prius with the A/C off and the window(s) open, he is actually increasing the air resistance of his Prius and is using more "petrol" than if A/C was on. Definitely a skewed test. Here in Canada we use litres/ 100km. Global warming is real. No blizzards now.

Jon Tennessen, Edmonton, Canada

Toyota and BMW deserve kudos for their attempts to reduce petrol usage. Sorry motorheads, but global warming is real! I'm almost 60 and I've watched it happen. Time to get your head out of the sand and get your foot off the gas pedal and onto the pavement. Walk, bus, bike or a combination.

Jon Tennessen, Edmonton, Canada

we drove our prius 10000 km in one month from quensland to western australia and lots of places in between. we averaged less than 5.5 l/100 km. We had 3 people in the car and could not fit in any more lugage than we had.
We often travelled all day at 120 kmh, and longest day was 1200 km.

bill sincliar, fremantle, australia

This comparison stinks. Anyone who has a Prius like I do knows this is paid for marketing, and you know for whom. Just today a member of Prius-PT community went on a urgent trip with his Prius with cruise control at 140 km/h, sometimes reaching 180km/h and did 6,3 litres per 100km! Do the math!

Joao Prates, Lisboa, Portugal

I have owned my Prius since Dec 05 and have covered 60000 miles. Toyotas claims are `Jackanory`. I average about 47mpg and it can go down to less than 40 for sustained high speed motorway runs. Personally I don`t care as my private fuel is paid for and it saves me loads in company car taxation!

Mark, Cambridge, England

As a lot of people posted on here, it is quite simple. The Prius is absolutely worthless if you are a frequent highway driver. It will act like a normal 4 banger car. However, the Prius is perfect if you are a city dweller that goes through stop-and-go traffic as often as a fish swimming in water.

Nick, Surrey, BC, Canada

The Prius is an iteresting vehicle but is far too thirsty for my kind of driving.

How does 93mpg sound out of my nippy Citroen C1 diesel and thats not an idle claim its the real McCoy.

Yep ive actually achieved that dizzy economy and my C1 is grat fun to drive.

Peter Lewis, Llandudno, North Wales

It is interesting that people always like to compare the fuel efficiency against Prius. The writers used the driving style that most of us won't have the chance to do in our daily driving to achieve the comparison result. By searching on the internet, I can see most Prius drivers get much better fuel efficiency than the article has indicated. For me, this article is just another marketing campaign. Unfortunately, this article has achieved its objective. (If you google BMW520d, you'll see many references to this article.) For sure, the BMW enthusiasts love the result. But discussing about diesel vs hybrid based on the result here is just wasting everyone's time.

Paul H, Melbourne, Australia

Why are Prius owners so concerned about any test including more urban driving. Havnt they heard of the train or bus! The test should have less urban driving, Prius just seems a conscience reliever for the town dweller that cant bring themselves to use public transport.

I also don t get the manual v automatic gripe, its about the most efficent mode of transport, now if by moving your arm and leg occasionly as you drive means it is more efficent, then why be a lazy bum, of course all that walking and effort changing buses and trains must be way beyond a Prius owners ability perhaps it does help to explain their thought process. Conscience without scarifice.

PS I walk to work, take the train(walking distance from office) for business meetings, get shopping delivered and/or work from home on computer. Sadly I dont get to drive my Range Rover much!! But a least Im not deluding myself driving 10000miles a year in a Prius.

Charlie Boggins, Reading,

Actually, to all those people saying the Prius does 0MPG at the lights and in stationary traffic, the BMW does 0MPG also. (Part of their new efficient Dynamics ma-larky) So the Prius isn't green at all. The only time i would consider investing in a bug-eyed Prius if I lived,worked and spent my whole life to the confines of London. Thats the only positive of it.

George, Chester, Cheshire

Fuel consumption is largely about driving styles. Mr Bonner, who averages 34mpg in his BMW 520 diesel is one of the accelerate then brake school of driving. I have an automatic 3 litre Renault Vel Satis diesel. Bigger than the BMW 5 series and an older generation diesel. Over the last 6 months of mainly short distance commutes to my local station and the occasional longer trip I have averaged 35 mpg. Not bad compared to Mr Bonner’s BMW. The secret is driving smoothly, avoiding using ‘kick down' unnecessarily and anticipation. On road I know well I regard having to brake as a bit of a failure. Too many drivers fail to use engine braking properly. I can usually keep pace with most cars along a typical main road rarely needing to touch my brakes, coasting into corners, judging how much speed to build up before the next corner, while the driver ahead is constantly braking then accelerating again. Overall we progress at the same pace but his engine and brakes are working much harder.

Kevin Miller, Tonbridge, Kent

nitrogen oxides are much higher on diesel engines, the small particles that are produced from diesel engines cause asthma, only 30% of a barrel of crude oil can be used to produce diesel, the price of diesel is high due to excessive demand, a diesel car really needs to do over 20.000 Miles a year to make it viable, repair costs are high. Diesel engines do release less CO2. Particle filters don't filter what they should. The only real alternative is an electric car. The future of long distance driving is not looking too good. Even Hybrids will not succeed in the long term. Bio-fuels will finally cost too much reducing any benefits even when associated to electric motors. Reduce your daily commute and start preparing yourselves for the last ever TOP GEAR! The Prius has given us a good base as consumers are now prepared to accept that combustion engines are not here for too long.

Gary Lawrence, Montpellier, France

I would like to add that when Jason coasted down the hill his 99 mpg is really much higher. The Toyota limits the mileage readout to 99 MPG. In reality it is much higher. Ask yourself what is my mpg when the car is coasting with the engine off? 100, 200, 1000 Miles per gallon? The same can be said for stoplights, the engine is not running but your not moving so you’re theoretically not getting any MPG, but in the BMW his mileage goes down. So if Toyota added the mileage saved at stoplight and raised the coasting limit beyond 99 the real mileage would be much higher.

Russ, Vancouver, WA

I have a BMW520D and over the past 3,000miles the average consumption is 34mpg (UK) according to the trip computer. This is a mixture of town and motorway driving at reasonable speeds. How the tester got 50.3mpg beats the hell out of me !!

B. Bonner, Altrincham, UK

What I want to know is how the test manages to make the Prius perform so poorly. Our lifetime average MPG on our 2006 Prius is 48 miles per (US) gallon, or 58 miles per (UK) gallon. 48 miles per (UK) gallon is 40 miles per (US) gallon.

This seems to happen every time I read a UK review of the Prius. Perhaps there's a difference between the UK model and the US model?

On long highway trips (75-80mph), we usually average around 52MPG, or 62MPG (UK gallon). I don't get how you could see results that are so conspicuously low.

Getting 48MPG (UK) / 40MPG (US) is HARD in the Prius in my experience - not once have I ever had a single tank that was so poor.

Brian Cairns, Boulder, Colorado, USA

This once again brings into question the 'official' quoted MPG figures. Real-life driving, no matter how careful, rarely achieves such figures.

The Prius is symbolic, but not green. The results are somewhat disspointing. We should all await the next generation hybrid diesels to see more impressive results.

The diesel petrol debate is age old. I have a small car, Citroen C2 and risked the diesel option at extra cost. My combined figures are a genuine 68-70 MPG, that includes mixed driving (motorway and urban), although I do confess that I drive very conservatively. I doubt that any petrol car could come within 10mpg of this figure. However, the car was more expensive and diesel fuel is too, so it depends on annual mileage. It does prove that some cars really are as economical as claimed.

MAW, South Yorkshire,

Was the extra 28 Kg of dirt the BMW produced really worth the 45 pence it saved on fuel?
And, as a real-life driver, I average 54 m.p.g. (UK) in my Prius. Sometimes I drive economically, sometimes I'm late-and-dashing. I once averaged 70 m.p.g. when I was stuck behind a truck on a narrow winding road for 1/2 hour!
I'll challenge this BMW - and I'll pick the route.

Mandy, South of England,

In a competition to drive to Geneva and "see who can get there on one tank of fuel", why is a 70 litre-tank car up against a 46 litre-tank car ?

Miranda, UK,

Whilst it's true that, because of how it's engineered, the most efficient way to get the Prius to speed is FULL THROTTLE (!), I have to dispute the claim that its poor performance is because it's a "low powered, small engined" car that's over-stressed by legal motorway speeds (81mph in france by the way, not 78 - learn your km/mile conversions!).

Please. I had a 45hp brick-shaped car with stone-age engine and transmission - that still turned in reasonable economy at 80mph. The speed requires about 36hp all-in with even mediocre aerodynamics (the old 34hp Panda 750 managed high 70s, flat-out). The much slipperier, advanced-drivetrain Prius, at 130km/h, will be doing the same as my own current 69hp car (1.6L, conventional petrol motor): Cruising, & using little more than 50% of peak power (at a relatively conservative 3200rpm, using ~75% of it's available output at that speed). Which, oddly enough, is more-or-less it's most efficient rev range/throttle setting. Gets ~39mpg UK @ 80mph!

MP, Birmingham, UK

Every time one of these "tests" proves that diesel is better, we quickly get knee-deep in misinformation. And forget the fact that the Prius driver has apparently never driven a Prius before. I suspect the Prius driver accelerated way too slowly, hurting his MPG while giving the impression that the car is a slug. Furthermore, he needlessly suffered with no A/C, when at those high speeds A/C's effect on MPG would have been small. This lets the pro-diesel folks "conclude" that the Prius would have been MUCH worse if not pampered. Look at www.greenhybrid.com for hundreds of data points by thousands of hybrid drivers over millions of road miles. Real-world Prius drivers average 47.4 miles per (smaller US) gallon. Total pollutants emitted: Advantage Prius. Let's also measure pollutants on these 2 cars after each has 100K km.
Finally, stop saying the Prius batteries have destroyed the area where they're manufactured. Google is your friend!

B. Goodman, Woodbridge, VA, USA

First of all, cars perform exponentially worse as wind resistance increases, and this is accentuated by engine size; a smaller engine at higher speeds will perform worse. Also, engine performance is highly based on how you drive; my sister gets about 33.5 mpg out of our hybrid civic, while I get about 49. By my observation and the things I've read, I would conclude that the test certainly favored the larger BMW, and that a fair test would take place at lower speed.

Daniel Costanza, Williamstown, MA

I drove a 520d over 2200 miles through Europe last year, and averaged over 42MPG American. I can also say with certainty that the car will attain its stated top speed of 144MPH (pictures to prove).

Andy, Tampa, US

The Prius is all image over substance and relies upon a 'right on' green mentality which has little basis in reality. I saw a similar example on Brighton seafront today. A small child on a wooden bicycle - no doubt bought for some riduclous sum in one of the trendy shops in the 'Lanes'. A useless thing, no pedals so the poor kid was pushing it along with his feet whilst other children whizzed by on 'proper' bikes. The future is just that, we won't save the planet simply by reverting back a century and a half!

Clint, Brighton, UK

kevin the new diesels do NOT put out particulates thats why it has taken so long for them to come to market in the US. Keep following the eco lemmings to prius nirvanna but 40 mpg on a US gallon is not worth the short comings compared to euro sedans with a modern diesel. Now if we were only able to build some new refineries we would be able to make enough diesel.

Jeff, San Francisco, US

..."are going to be worried when petrol is ten or twenty pounds a gallon?"...

At this price, oil shale production becomes feasible, giving more than 100 years of extra oil reserves. Thus the price quoted will never become reality. In any case we are not addicted to oil, only to energy. Other sources come into play when oil becomes too expensive. Yet another shameless piece of alarmism by the green zealots.

Tom, Alton, England

No-one has ever said the Prius gets the best mpg when driven like a sports car. The trip computer is there precisely to give the driver feedback on what types of driving aren't going to get you high mpg. The car also wasn't designed to get 50mpg at 75mph, uphill, into a headwind. It shines when there is typical urban traffic congestion, from stop and go (prevalent in CA urban areas) up to a congested 65. In those circumstances, which is what the car was built for (high density areas needing better air quality/vehicle), you can get well over 60mpg averaged over an entire tank (including hills and wind). This brings up the second set of points - even high-tech diesel engines put out a lot of particulate, diesel fumes are known to be carcinogenic (including: there are swaths of lymphoma outbreaks here in LA along the trucking corridors), and low-sulfur diesel (all we can get in the US) is more expensive than 92 octane petrol. Lead-foots can go faster with diesel, but at everyones expense.

Kevin, Los Angeles, CA

2004 TDI.

considering the above test, 560 miles or less on a prius tank is ok, but I'm getting 600+, at 48 mpg.

I usually go from tn to nj on one tank. Nothing makes me laugh more than watching a prius zipping down a hill at 80+, only to see it sputter at 65 going up a hill.

If you want life in the slow lane, get a prius. If you want to take the left lane and hold it comfortably at 90 mph, any incline, get a vw.

mark, knoxville, usa

I really wish more excellent diesels and turbo diesels were available in America. My next car will be one if it happens.

Sam, New York, USA

I see something that is missed here.

We have two cars that get nearly 50MPG! That is fairly awesome. And look at them. One is a high tech Hybrid, the other a hidh tech Diesel. Shoot, the BMW is a 5 series.

Imagine what the 118d (which we won't get here in the US) would get if compared to the Prius.

I think instead of trashing either one, we need to realize we can get to about 50mpg in several ways, and a hybrid is just one of them.

The Prius is only part of the equation, and Prius owners who are 'Smug' should also be happy that another car is in the same range, and even bigger.

As I see it, that a BMW 5 series can do it, more vehicles can. I want to see what the Gm 4.5ltr Diesel does in a car, since it can hit 35mpg in a truck. :)

Josh, B'Ham,

I cannot believe these people are admitting to driving a "Prius" eugh. Give me a proper motor any day, bugger the emissions what speed will it does is most important.

Mike Durrans, Barnstaple, Devon

The defence of the Prius is very commendable, but why produce something that is more complicated, costs more in emmissions to manufacture and has higher final disposal cost - when the supposed "gain" in emmissions is neglegable at best and probably non-existent in real life driving?

B Hobson, Birmingham, UK

Regarding:

"The increased tax rate is a reflection of a misperception that Diesel Vehicles pollute more"

It is true. It's still very conentious to call CO2 a pollutant but carbon monoxide, unburnt hydrocarbons and oxides of sulphur and nitrogen most definitely are and diesel engines produce them in far higher quantities than the equivalent petrol engine. Diesel engines are less efficient at properly oxidising all the fuel, including carbon, so their CO2 levels are low for the wrong reasons. As for hybrids, the toxicity of producing and disposing of the batteries at either end of their lifespan completely outweighs any pollution advantages. If combustible fuels have to be used, we should be concentrating on ethanol or hydrogen, and definitely not diesel.

A. Taylor, Edinburgh, U.K

Nobody cares it puts out less carbon. We only care that we can drive a BMW 5 series and get the same (fuel) running cost as a supposed "green" car.

Don't like it? Build a better car than the 3 series and make it a hyrbid.

Matthew T. Brown, Glasgow, UK

Interesting article - as many have said - set up to show BMW at best. However, what none of the comments I've read, have pointed out that the Prius still emitted less CO2. Diesel emits 12% more CO2 per gallon than petrol, so the BMW needed to do 53.9 mpg to "win".
BMW do make absolutely superb diesels - probably the best - and a 3 series would be a fairer comparison to the Prius for size.
I'm really keen to see real world tests like this so I'm sorry the Prius driver put themselves out so far. But really, once again, the Prius was not actually beaten despite being given a test weighted against it.
Now, how about doing it again with a Prius vs 320d (preferably Auto) leave N London at weekday 8am, driving North Circ then M40 to Birmingham, cross B'ham city to pick up M6 to Manchester, through centre to M62, across to Bradford - Leeds - A1 back to London. Each car driven 50% by each driver. I'll even offer myself & my Prius :-)
I'd be seriously intestested in this result !

Mark Brockbank, Leeds, Yorkshire, UK

The only reason that Diesel Fuel is priced so much higher in the U.S. is that it is taxed at a higher rate (both at the company level and directly at the pump.) The increased tax rate is a reflection of a misperception that Diesel Vehicles pollute more, and should thus bear a higher tax rate. All things being equal, Diesel Fuel costs less to manufacture, and if the political correctness would end, Diesel Fuel would cost less.

Stephen Bennett, Merrimack, New Hampshire

Statistics notwithstanding, the Prius has a tremendous following and this is an indication of the fact that people are not much more conscious of things like the environment, pollution, emissions and their own carbon footprint. The fact that petrol prices are going thru the roof may have something to do with it :). The popularity of electric vehicles (http://www.zapworld.com) also bears out this fact

NiraliSherni, Bangalore,

Statistics notwithstanding, the Prius has a tremendous following, and that is an indicator of how conscious people are becoming of the environment, emissions, pollutions and their own carbon footprints. The popularity of electric vehicles such as ZAP's (http://www.zapworld.com) also bears out this fact.

NiraliSherni, Bangalore,

I've just returned from the States, and can understand why diesel cars are so rare. Diesel fuel is over $1 per gallon more than petrol ($4.40 vs $3.35 per gallon), around 30% more expensive!! Given that diesel powered cars are around 25% more fuel efficient, it is actually more expensive to run a diesel car in the US!

T Lim, Peterborough, Cambs

I live in Tennessee, USA. There is only one new diesel passenger car for sale here (Mercedes-Benz E320 BlueTec 3.0 V-6) and it is available in only forty-five states. There are three MB SUVs and one VW SUV; again only forty-five states. VW had to discontinue sales on the VW Jetta TDI, New Beetle TDI (1.9-liter) because, being unit injection, could not be fitted to NOx-reducing equipment. No automaker has been able to bring a fifty-state emission-legal car here, because our EPA has changed emission laws to require diesels to meet the same limits as gas guzzlers, while simultaneously neglecting to allow developed technology to meet these limits.

May 2007, the EPA finally accepted SCR, NOx-abating technology with very strict parameters. Systems then had to be designed by automakers to fall within those parameters. This fall and winter MB, VW, BMW, and Audi will soon offer very clean, fifty-state certified diesels here, but Americans know almost nothing about modern diesel technology

Greg, Rickman, Tennessee, USA

USA--I'm a diesel-power fanatic. I drive a 2006 Jetta TDI. I consistently get 44 mpg (average US gallons), but our EPA estimates this car at a modest 34 mpg (city/hwy combined rating), and this is running 20% biodiesel in the blend. The EPA gives the Prius a 48 mpg, overall rating, which is a farce. These cars probably come in around the same in regular, high-speed, highway driving.

Most Americans will not take the time to try and understand the benefits of diesel power that could be especially pertinent in a country that does alot of highway commuting. An EPA spokesperson has stated that America could save 1.5 million barrels of oil per day if our personal transportation fleet were 1/3 diesel powered, but the media has not spread the news.

Most Americans equate diesel power to heavy equipment and do not equate diesel power to petroleum savings, refined driving, or CO2 reducing. Most certainly, most Americans do not relate diesel power to high performance.

Greg, Rickman, Tennessee, USA

USA --It will be a challenge promoting clean, diesel power in the U.S. The exhaust-treatment equipment added to the premium cost of a diesel power train increase the cost about $3,000-$5,000 per unit over a naturally-aspired, IDI gas engine. Applying this premium to small platforms will be difficult in America where drivers are used to paying US$14,000 for subcompacts. Diesel fuel averages $.35 per gallon more than gasoline; it's $.82 per gallon higher right now.

People do not equate diesels with cleanliness or refinement or as a method to reduce petroleum consumption. Renewable diesel fuels have not thrived here nor do consumers understand this added benefit. Diesel fuel is not at all retail stores.

Still, there will be twenty-five, super-clean diesel choices here by 2011. Maybe automakers will be able to demonstrate the worthiness of this superior power train. If not, the marketers will give up and we'll be stuck with only hybrid choices as a method to improve fuel economy.

Greg, Rickman, Tennessee, USA

This was not a "test". It was an attempt to belittle the Prius and anyone driving one and promote old technology and gas guzzlers. The Prius was designed for the town conditions of today, London, Paris, New York and Tokyo. Stationary or in slow moving traffic the emissions of a Prius is nil while the BMW and all the other cars using old technology are churning out their poison. The run through France was on one of the least crowded roads in Europe. Driving through Reims even in the rush hour takes about as long as doing a mile along the Great West Road in London at the same time. We need to wake up and realize that the oil is running out and fast. Get behind new technology and demand cars that will do 100mpg not 55 in ideal conditions. Do you think Clarkson and his ilk are going to be worried when petrol is ten or twenty pounds a gallon? No, it will mean that they will be able tear up the motorways that much quicker, because few of the rest of us will be able to afford to go anywhere!

Harry Pritchard, Newport, England

I've had a Prius for almost 2 years. My fuel consumption varies between 55mpg and 62mpg. Last year we drove from Sydney to Noosa, which is a 1300km journey and got 62mpg.
The problem with the comparison of the Prius and BMW is that when you travel at 70 mph for an extended period, the electric system only benefits in adding torque to the wheels occationally and then extra fuel is required to charge the battery up again.
The comparision in this case is between a 2 litre diesel and an efficient 1.5 litre petrol motor. So the diesel wins.
If the test restricted the drivers to 60 mph and you took your time up the hills and let the batteries charge down the hills the story would be different. Unfortunately the battery is only 1.2Kwh and the recharging is limited to a contant low current, which means that you have to go slow to get maximum efficiency. Better batteries is a must.
The prius hybrid is now 10years in development, and the diesel is over 100. Let Hybrid technology grow.

Walter Koeller, Kiama,

I'm just back from a wee trip to Cambridge to my home in Perthshire. My car (Accord Tourer 2.2 i-CTDI) averaged 55.7 miles per gallon and travelled 708 miles from 58L - 12.7 gallons of BP Ultimate Diesel. I'm glad I bought a Honda and not a Toyota or heaven forbid, a BMW! ;)

john, perthshire,

Its interesting reading the comments that the vast majority of those who are "pro" the Prius reside in the USA - I wonder if that has anything to do with the fact that diesel engined cars are much rarer over there and thus most people actually haven't seen what a modern diesel engine can do or something to do with US people being more susceptable to the dubious claims made by the Honda advertising....

Or is just that they've seen all those "celebs" buy one and decided they must do the same to keep up?!! ;-)

B Hobson, Birmingham, UK

Interesting comparison. Last night my wife and I averaged around 66MPG in her 5 speed manual Honda Insight with the AC on and the motor running at stops ( you can override this in the Honda ). We actually approached 70MPG at the end of the first leg of the trip ( round trip around 60 miles slightly hilly terrain, some stop and go, highway driving 35/65 mix with speeds from 35 MPH to 70 MPH ). Not bad for 2005 technology. I think the things that helps us get good mileage are knowing how to drive to the strengths of the hybrid, a real time gas consumption gauge, a cd of .24, and proper tire pressure. As VW announced their new Golf Diesel Hybrid and other manufactuturers to follow, we should see more high mileage cars enter the market. I look forward to when the strengths of the diesel and hybrid are blended together. Our car isn't perfect but a lot of fun to drive, especially when you fill up about once a month.

Bob Rodriguez, Raleigh, USA

Lets get real over this. Most people never ever match the claims of manufacturers regarding consumption and its obvious here that Toyota must have skewed their own tests to achive their claimed 65 MPG. All manufacturers could design a car to meet a very narrow set of driving parameters and achieve a high MPG rating but what use would a car like this be. Except for a small trial run in France for electric cars in a few French towns, no one wants a car that is good in town but lousy on the motorway or vice versa. The surprising thing here is that despite shutting down AC and other non essentials it didn't appear to buy the Prius anything on consumption and it actually fared worse than a large 520D. The special treatment that the Prius gets from government is another con by Labour who spin their eco credentials when in reality they have none. Diesels were in, then they were out and the government is forever changing its mind on dubious research. Does anyone really know the truth.

Mike, Alicante, Spain

If you really want to save fuel you can do some research first. This story was run in USA Today June 10th 2004. The BMW 520d was replaced with Volkswagen's Jetta GLS 2.0. 22 gallons to prove the same result!

Gabriel Byrne, Houston, TX

Simple solution, don't drive in an urban environment. If I go to London (God forbid) I drive to somewhere like Richmond and then get the tube. Then you don't have to buy one of the ugliest cars in the world...

Mark, Taunton, Somerset

The Prius is not just about fuel economy and your article misses one of the main points of the car which is to cut down on CO2 emissions.

Joe Burns, Formby, Liverpool, Merseyside

Sorry Mark from Minneapolis, it's the other way round. If Neal is getting 52mpg from a US gallon, then he would get 20% more from a fat UK gallon.

C Byrne, Pinner, UK

This is a fatuous article. If you are going to drive to Geneva (average journey speed 78mph), drive a BMW. If you are going to take your kids to school in London traffic (average speed 11mph), drive a Prius.

Zac Smith, London, UK

Hybrid technology is not worth investing in. Ships and locomotives are propelled by electric motors. The motors are powered by generators which are turned by diesel engines. This technology will soon be available from GM in the concept Volt which has shown in tests to travel 40 miles just on the batteries, or switch over to flex fuel or biodiesel and get 150 miles per gallon. A small engine turning a generator continues to provide power to the electric motors, but never has to sacrifice fuel economy during acceleration since it is not the source of propulsion. The only real question is why wasn't this technology perfected years ago and already released to the public so pricing would be affordable by now. Guess the oil companies could not have record profits every quarter if our oil consumption was cut 80%.

Terrell, Brunswick, GA

Neal, Portland, USA / Oregon said "I've driven a Prius for two years now (almost 40,000 miles) and average 52 mpg combined. Granted, I drive conscientiously, but I can't begin to imagine how hard you'd have to drive the car to get 40 mpg. On the Interstate at 70-75mpg I still get 46-47 mpg. Something's not right here, maybe a little European one-upsmanship trying to discredit a superior automobile made on another continent?"

Neal, they were using miles per imperial gallon. One imperial gallon is 1.201 U.S. gallons. So, if you converted your mpg to miles per imperial gallons, then you would be getting 43.3 mpg and on the highway you would be getting 38.3 to 39.1 mpg. They were actually getting much better mpg than you do. The Prius got 57.8 mpg in U.S. gallons. I would say the superior automobile is definitely the BMW. It got better gas mileage even with the ac and radio on vs the Prius driven without those. The BMW isn't a slug accelerating either.

Mark, Minneapolis, MN

I just bought my 2008 Prius and I love it. I am saving time and money with less trips to the gas station. I brag about my mpg compared to my gas guzzling Porsche. On the average I get 41- 42 mpg commuting to work and I am driving on the freeways and city streets daily to get to work. During the weekends on city streets, running errands, I get about 48 mpg. So... the Toyota advertising is a bit of a stretch.

Janet Hwang, Aliso Viejo, CA

I know a lot of people here in the U.S. who owns Prius. They get like 45-50mpg. I was this winter in Bosnia and drove my parents Skoda Octavia 1.9tdi. I got regulary without much trouble at least 50mpg, while once i tried to see how much i can save, I got like 57mpg.
Now, I got 45-50mpg driving regulary to mountains for skiing, so I would like someone to tell us how much Prius spends in that kind of conditions, uphill driving and temperatures almost 20 below zero (celzius).

Edin, Montgomery, USA/Alabama

Many above commenters miss some key points. The BMW combines light hybrid (regenerative braking), diesel, manual tranmission, and a convenient, real-time fuel economy guage.

Contrary to what some have indicated, regenerative braking can be significant in highway driving. Note, also, that the manual transmission was credited with a 10% mpg boost. My experience is that regen braking responds faster with MT than CVT. The MT Civic was also rated somewhat higher than the AT Civic. With MT, a good driver has much more control over gear ratios than with the CVT transmission.

From my own experience with my 2003 Civic hybrid with manual transmission, I think a well used, clear, real-time MPG indicator can be as significant as hybrid as a contributer to gas mileage. The MPG indicator and charge/discharge indicator on my Civic are both much more useful than the ones on my wife's Highlander Hybrid.

Aerodynamic features are not always obvious. Is the Prius really slippier?

Eric, Pleasant Hill, USA/California

I've driven a Prius for two years now (almost 40,000 miles) and average 52 mpg combined. Granted, I drive conscientiously, but I can't begin to imagine how hard you'd have to drive the car to get 40 mpg. On the Interstate at 70-75mpg I still get 46-47 mpg. Something's not right here, maybe a little European one-upsmanship trying to discredit a superior automobile made on another continent?

Neal, Portland, USA / Oregon

what i can't work out is why ,with all this technology going into cars and making them more fuel efficient .
We are still using 1950 style traffic lights with a wire under the road and timers controlling the lights.
Why not have motion sensors that detect cars approaching and trigger the lights before you get there.
That would save everyone more gas as well.
Hats off to the BMW engineers for this one!

Craig Jull, Anaheim, USA

Paul from Worcester...more fuel=more CO2!! However, diesel engines have a higher CO emission figure than gasoline engines.
Therefore the PRIUS is useless as a "combined" car. It is not in the overall sense more environmentally friendly than a standard diesel engine.
Same thing with wind turbines....expensive in terms of energy to build & expensive in terms of maintainance.

Mike, Wawa, Polska

The three people I know in the US who own the Prius get 45-55mpg regularly in commuting. An efficient diesel in the Prius would get you how much better mileage? Not an exact tech comparison but it does show that the major auto companies can create fuel efficient cars if they want to. No excuse not to raise the corporate average fuel economy to 40 or better in the US.

Richard Campbell, Alexandria, Virginia, USA

Working in a city far away from my and my fiancee's family, the most ecological use of today's technology (apart from using public transport and trains) would be to have a morern diesel engine car for out-of city trips, and take a hybrid-equipped taxi in a city;-).

On a side-note: it's obvious that prius will do badly on highway-speeds. The volume of it's engine is just around 1.4 litres, I think, so it has to be less efficient than a modern 2-litre diesel engine. Prius runs almost purely on the gas engine part of its hybrid at those highway speeds.

What's say about the automakers is that virtually all companies are lying about the mpg, or fuel consumption in mixed conditions. In my experience, I can never achieve as high mileage (as low consumption) as they declare, no matter how slow I drive, or on how low acceleration, high gear I drive.

Martin, Prague, Czech republic

What matters is not consumption but emissions; what were the real world CO2 emissions from the two vehicles during this test?

Paul, Worcester,

I'm not sure this is a viable test. The Toyota salesman trying to sell me a Prius admitted up front that the Prius is not a "commuter car". It gets its best mileage in town, when starting/stopping/turning/coasting up to red lights. On the highway, the power generation system doesn't get much of a chance to work (except when coasting down out of the mountains LOL). So, in this test, the Prius was running on a long-distance run, probably burning gas most of the time.

For a better comparison, I would like to see the authors of this article compare the same two cars whilst driving around town for two weeks. I have a feeling that the poor fellow with the Prius will come away feeling MUCH better when he still has half a tank of fuel left, while the Beemer had to fill up two or three times in the same span of time!

Mike S., Kansas City, Kansas, USA

Had a Prius for a week while the BMW dealer took the dash out of my M5 to find a whistle in the AC. Averaged 40.1mpg driving in mixed conditions with the same level of right-foot I'd use on the M5 or anything else we own. The M5 gets 17mpg in similar conditions. The Prius powertrain worked okay, the rest of the car sucked - lousy outward visibility, crappy driving position and controls, no sense of straight-ahead, hobby-horse ride like an old 4Runner.

The only reason to own a Prius is carpool lane access, or because you're the kind of eco-symbolism groupie that I'll happily exile to my Alaskan backwoods gulag as soon as someone makes me King.

John Miller, Foster City , USA/California

Interesting discussion. I like the idea of economical motoring, but also saving myself money whilst doing it. Therefore, with current fuel costs in my local area, petrol at £1.029 a litre and diesel at £1.109, an 8 pence difference, just over 36 pence per gallon difference the above would favour the Prius. Also for the company car driver, whilst the Government extol the virtues of the hybrid (from April 2008 taxed at 10% down from 12%) and the BMW falling into the 15% category from April 2008, again the Prius would win on saving me money at either 20% or 40% tax rate. I would concur with those that do more city driving (especially London) and look to the Prius, but for the longer distance motorway cruisers amongst us, diesels cannot be beaten.

Angus, Leeds, UK

Here's my "smug": I own a 2001 Prius, which I have driven since it was new. I have a friend who has owned a succession of Volvos, Beamers and other vehicles. My Prius has been involved in several accidents over 7 years, crossed the country twice and is approaching 150k miles. Still runs like a dream. My friend is on her seventh car since I've known her (almost as long as I've owned my Prius). I fill up, on average, once a month. She fills up once a week. We're about the same distance from home to work, and both live in the fourth largest city in the United States.
True economic viability is in the lifespan of a car. I would say the Prius is a success.

Michael Lynch, Houston, Texas, USA

I have a Toyota Corola Verso 2.2D which has just given me 49.10 MPG on a 200 mile journey in pouring rain which included rural, urban, high speed motorway and 20 miles in the Peak District in thick fog over a mountain at 15/25 miles per hour in third gear!!
Not bad with one passenger and the heater/wipers going non-stop(aircon off).
But, after all, this was the only MPV that J.Clarkson recommended.

AWilliams, Cradley Heath,

The Prius is a lousy hybrid with a third-rate transmission.
We need to see a torortrak hybrid with the Flybrid regenerative braking system to see what hybrids can actually acheive. This would blow the beemer out of the water on motorway cruising.

Andrew, Brighton, UK

I have a Fabia 1.4TDi estate - it has a larger boot than the Prius, is in the same tax band and costs nearly £6k less than the Prius - in addition I can run with the aircon on and based on previous trips to Europe I would be extremely disappointed if I was getting less than 60mpg on the trip they have described.... the Prius is a con trick as is the Lexus - if they really want to produce a low emmissions hybrid then use a small diesel with particulate filter instead....

B Hobson, Birmingham, UK

The comparison is additionally unfair as it doesn’t take into account the total environmental cost of the production and ultimate disposal of the NiMH battery packs which are expected to last only around 100,000 miles. Some analyses actually suggest that Prius is one of the most environmentally expensive cars currently on the market.

Congratulations to Toyota for the triumph of marketing hype over reality. The tactic of starting with the Hollywood types was the key to this.

Kyklos Vitruvian, Cincinnati, Ohio, USA

Hi Nicholas, Be careful with BMW's brake energy regeneration system. It is not like Toyota's Prius at all. The BMW does not have generators in the wheels or attached to them. What happens is the BMW disengages the alternator when the car is accelerating so that all the engine power goes to the wheels. It is only when the driver lifts off that the alternator is engaged, driven by the engine on the overrun. Clever, but not the same.
Cheers from Down Under

IP, Melbourne, Australia

this bmw diesel has regenerative braking like the prius . other diesels aren`t as economical . they are also polluting much more (HC,NOx and much more). when they are getting older they are polluting especially bad in comprasion to comparable petrol engines (when they are after warranty few owners service them e.g. changing catalysts and filters) . one liter(gallon) diesel have about 15% more energy than petrol becouse of it`s densier about 15% and that`s why it emit after burn of one liter about 15% more CO2 . So in this test prius needed fewer energy and emitted fewer CO2 even if it burned more litres of petrol than bmw litres of diesel.

john, rybaki,

Quote <my wife, she doesn't like the smell of diesel fuel!>

Presumably she prefers the nice sweet smell of Petrol?

That nice sweet smell is highly carcinogenic (and very aromatic) Benzene which according to the World Health Organisation has NO safe exposure level. Unleaded petrol is 2% killer benzene and you don't even need to burn it to kill yourself with it.

try that test with a bigger Lexus and the BMW would win by an even bigger margin.

Vote Toyota for con trick of the century, the last one as they've been rumbled in this one.

Steve Canner, Cambridge, UK

So the Prius managed 48.1mpg overall in real world test with 1 person on board, not using the air con or the radio, and with its slippery shape, hybrid technology et all.

I drive a Nissan X-Trail 2.2 dCi and well the best mpg I've managed is only 42.2mpg in the real world, but I did use the air con and the radio, I had two adults and three kids on board and had a full boot, all in a car as slippery as a housebrick, oh and with nothing more than standard diesel technology!
I hang my my head in shame for being 5.9 mpg short from beating a Prius in loathsome 4x4!

Steve Jordan, Southend, Essex, UK.

One thing that has not been mentioned in any of this is the much higher emission of NOX by the diesel engine. Its hard to weigh the relative values of different pollutants but we do seem so fixated on CO2 these days that NOX hardly gets a mention and none at all in this article - a significant oversight in my view.

Colin Mill, Glossop, Derbyshire

This was entirely unfair - should have used the BMW 118d instead - it's much more comparable in size and function to the Prius. Okay, it's cheaper and much more efficient than the 5-series as well...

Matt, Bristol, UK

If you think that's impressive look at the Mini D! That's cheaper than the Prius and smokes it on fuel economy!

Jeremy, Tampa, FL, USA

Also, given the fact that diesel was $3.07 (US) vs. regular unleaded at $3.29 per gallon today at my local fuel station I'd take anything diesel from BMW or Mini at this point!

Jeremy, Tampa, FL, USA

Mr. Smith-Moorhouse seems to be confused as to the type of propulsion batteries used in the Prius. . The Prius uses nickel-metal hydride(Ni-MH) batteries not lead acid. These batteries are recyclable and considered environmentally safe. In fact, the nickel content in these batteries makes them profitable to recycle.

Devin DiLibero, Los Angeles, CA

The comment about dangerous heavy metals polluting the earth at the end of the battery's life cycle misses the point. These heavy metals (Pb, mostly) are too expensive to dump in a landfill somewhere. They will be recycled, by economic necessity

Micheal LeVine, Port Jefferson, New York USA

There are clearly a lot of Prius lovers here, but come on you've been had by some truly excellent marketing people at Toyota. The Prius is a good idea in principle, but its terrible for the environment when you consider cradle to grave energy use. Plus lugging around all of those batteries is hardly efficient. Then think about this, for every extra bit of fuel you use, a bit more needs to be pumped from the earth, then refined and then transported to the fuel station. All those lovely lorries carrying fuel to put in your Prius. Buy a Ford Focus 1.6 TDCI. You'll get more mpg, enjoy driving it more, plus its cheaper to buy. Plus it only emits 15g/km more CO2.

Finally, whatever anyone says, this was a fair test and it clearly states they deliberately went along urban roads to give the Prius a chance. Factor in the BMW driver having his aircon on and that a CVT is actually better than a manual, certainly no worse, you have a clear winner.

William, Chelmsford, UK

How is the class action against Honda in Los Angeles USA by buyers of the Civic hybrid which has proved very disappointing in practice? Hybrids are only more economic is heavy traffic where the engine stops and starts when the car does, otherwise on a journey, it still needs he same amount of fuel to do the kilometres as a similar power output and weight car. Our 2001 Ford Focus Diesel TDDDi has averaged 47 mpg over 138.000 Km in all sorts of traffic including climbing the very steep hills here with no special economy driving, just good normal not hanging around driving. The newer models are much better so why go to the complications of toxic to dispose of batteries and low power cars. It is a con! Use diesel with special exhausts to clean the pollution up.

B J Deller, Marbella, Spain

I like that someone has finally prooved that the Prius is not the all singing all dancing tree hugger that everyone thinks it is. People buy the car because they think its the socially responisble thing to do. If these people weren't such sheep they would realise that if they did want to be socially responisble in respect to the environment they would look into matters further realising the Prius has big lead acid batteries with a short lifecycle (in comparison to the average petrol/diesel engines). these batteries contain un-recyclable heavy metals that are VERY dangerous to our environment. So wheres the bonus if a normal BMW saloon beats it in mpg. most people driving a Prius are still doing journeys alone, so why do you need such a big car? readers say they get 50mpg from a Prius... but I get nearly 70mpg from my non-hybrid, 99.9% recyclable completely standard Citroen C1... give me one good reason why we should be giving tax cuts to persuade people to line Toyotas pockets?

Jon Smith-Moorhouse, Loughborough, Leicestershire

As with all propaganda - he who advertisings and pulls hort tricks wins.... like the betamax and VHS video war, both were reliable and compatible and in the greem light - nowadays - betamax would have won on reduced unit size and amount of plastic used!!!! or VHS would win saying "we use more recycled plastics than Betamax!!!"

Its a marketing game that is won and lost - at the end of the day - new technology will win - Prius was leading edcge 2-3 years ago.... now BMW has stepped upto the marque!!!

BMW wins for me which is why I bought one last week!!!

on normal work runs and weekend tottering averaging 48mpg 684 miles per tank, a shade short of the 700 publisised!!!

but in the brichure - figures are based on a person of 65kgs!!! me being at 90, 2mpg incentive to lose weight!!

Terry Hastings, reading, UK

Todd in USA - 49 litres is 10.77 UK gallons so the math is correct

John, Norwich, UK

You also have to indicate the BMW ( had a 735 and loved it) cost 7000 pounds ( $14000) more which is a lot of fuel.

Don Wojtas, San Jose, ca

I recently purchased a BMW 520D, taking delivery last week, and it will be an interesting comparison against the Audi A6 2.0TDi it replaces. In that I averaged over 42mpg from 47,000 miles, mixing commuting with motorway driving.
If I can nearly match a 'real world' Prius in the Audi, what will the BMW deliver -The BMW has 25% better fuel economy , 25% less CO2 emissions and 25% more power than the Audi.

Bob Fennelly, Horsham, England

ok... We don't have the small diesels in the US. Fact is the prius is about the only car we can buy to get halfway decent gas mileage. One note... you are paying more for the diesel fuel here in the US.

Tom , Sunrise, FL

A year ago I had a look at the Prius when deciding on my new lease car. After reading the comments of various owners, I realised it wasn't all it was cracked up to be, and got a Peugeot 207 diesel instead.

60+ mpg overall is very nice.

Michael Smith, Southampton, UK

The Prius is optimized for maximum efficiency in stop-and-go city traffic at speeds under 40 mph. If more than half of your miles is highway driving (i.e. you commute 50 miles each way to work every day at 75 mph), then the Prius isn't the most economical choice: you'd be better off with a small conventional gasoline engine, like a Toyota Yaris, Ford Focus, or Nissan Versa.

Hal Durland, Ithaca, NY, USA

Being an economically minded chap (but I think global warming is a crock. ie worst polar melting since records have been kept. How long have you been keeping records? Since 1979. Hardly geological) we looked at buying a Prius. We had previously hired one whilst in the US. When we had the test drive the plastic interior looked really worn. It turned out the thing was only 3 months old but I would have said 18 months. The salesman confirmed that no one could get the mileage claimed & he was using it to commute. Finally we established even with govt. subsidy this thing dropped in value like a stone. So our conclusion was that only a Hollywood, easily influenced, brain removed, green wannabe, private jet & Ferrari owning millionaire could afford one. It also seems that when all the build/recycle costs are considered it is not that green (like Dave's wind turbines political points 10. Green points -10). So now we are the proud owners of an Audi A3 diesel. Fantastic car.

Bill Green, Walsall, UK

I bought a new 2005 Prius including all options at the time, and have driven it 20,700 miles in 3 years in comfort and enjoyment for all its features. Contrary to Toyota and the EPA est. miles per gallon, I average 39mpg in avg. driving conservatively.
local G.W.Bridge New Jersey hilly area; 45mpg avg. highway driving at 65 to 75 mph not having exceeded 150 miles in any one way trip. (300 mi. round trip).
Although the cost of gasoline is cheaper than diesel fuel in this area, I would like to see Toyota try the diesel-electric hybrid approach using the best diesel (BMW?) engineering for greater fuel and conservation savings.
In comparison I drive a 1983 Porche 944 manuel 5 gear(less often now) which gets 19mpg locally , 36 mpg long trip highway .
I bought the Prius because of its environmental and fuel conservative features as well as for its engineering design.

Paul Friedman, Fort Lee, New Jersey

I am mistaken or does diesel engines produce less carbon emissions ? That would make the bmw a clearer winner

Olivier, London, UK

Take that tree-hugging bearded delusional environmentalists!

From a 5 series BMW owner.

Daniel, Wellington, New Zealand

More evidence, as if any were needed, that people will pay good money to hear what they want to hear. My 7 year old worked out the flaws in this piece of junk.

Peter, Vancouver,

Well Sir Jeremy Clarkson has been saying it all along, the Prius simply isn't all it's cracked up to be.

Sir Jeremy has also made the point before, that it needs two factories - a one for the car and another for the batteries, and it just confirms, that quite simply, if you are after economy you must buy a diesel (or better still, if the numbers add up, a petrol engine will probably be just as good, owing to the lower initial purchase price)

Hassan Azam, Banbury , Oxfordshire, England

Todd (Indiana), you’re confusing Imperial and US gallons.

Keith, Luxembourg,

The guy in the Prius compromised his driving experience by not using the stereo and risked his safety (and that of others) by switching off the air con and making himself uncomfortable whilst on a very long journey.
And still the eco-warriers try to justify themselves and their choice to succomb to spin by buying second best by wittering about bladders and reduced emissions.
Wear your hair shirt with pride - I remain of the view that you are kidding yourselves.

Peter Schofield, Newcastle upon Tyne,

Todd,

This is from a British website, A U.S. gallon and a Imperial Gallon are not the same. 49 litres = 10.78 Imperial gallons.

545 miles / 10.78 = 50.55 MP(imperial)G

Tim S, Rhinebeck, USA / NY

Why has the wolrds 'knowing elite' rejected all arguments of the Indian scientists, whom have spent years in the southern Pacific / Antarctic, whom adamantly claim global warming is a NATURAL phenomenen, ( and that the GAINING of ice mass in certain regions is conveniently dismissed ) and NOT created by man - but then of course the governments would have lost out big way in taxation - easy come = easy go !!! - there is too much hype, especially by the USA, wher of course getting into your bigbore 6 litre pickup truck to go get a Big Mac half a mile down the road is 'their rights' !!!! - spare us !!! lets hear some truths from others !!

Pete, Arundel,

Peter Quill - the BMW has a particulate filter like all modern diesels. The gasoline cars of the future may need them, because particulate numbers, especially from direct injection gasoline engines, are alarmingly high, it's just that the particles are tiny and don't weigh much. Actually this could make it worse for air pollution.

Thee trial also doesn't mention that the Pious is smaller, slower, nastier, tackier and all round worse in every aesthetic way possible. Diesel wins hands down.

Jon Cooper, herts, UK,

Diesel fuel has about 12% more energy per gallon, so the diesel actually wasn't more efficient. Miles per kg of fuel would be a fairer measure.
Also, it's daft doing a test that's ideal for the BMW (high speed cruising). Do another test in a city!

I have an excellent Honda 2.2 diesel for long journeys and a Civic hybrid for use around town. Each technology is appropriate for different driving environments. My hybrid gets 50 UK mpg around town. I'd like to see the BMW get that.

Philip Hughes, Oxford,

I can make diesel safely and cheaply in my garage. I can't make gasoline.

Even if the mileage differnence is a wash, I'd go with the diesel.

Also, folks need to add the longevity of the diesel engine. It's going to outlast any fancy hybrid.

alex, warrington, UK

Yes Todd, you missed the fact there are 10.77 gallons in 49 litres in Europe. Hence 50.5mpg.

Peter M, London,

Thank you for printing the truth - but you'll be in a lot of trouble from the eco-mentalists who have declared the Prius to be an object of adoration!

Taking "whole life" emissions into account the Prius is actually one of the least environmentally viable vehicles it is possible to buy - despite its magnificent posing value!

Incidentally, does anyone know HOW (or even IF)they ensure the Prius doesn't spend most of the official fuel consumption test running off its -precharged - battery?

Mike Bibby, St ALbans, England -not EU

Bob the automatic vs. the manual transmission is significant, but don't you think the fact the BMW driver used the air conditioner and the radio while the Prius driver did not would nullify any advantage the BMW had?

Mike C, Lake Como, Fl, USA

The debate will rage on but what is clear is how deceptively easy it is to be brainwashed by the media, the authoratative voice of celebrity and the sometimes mindless singlemindedness of environmental campaigners.
In the life of a vehicle from manufacture to disposal which do you think will be the most environmentally friendly - the BMW or Toyota? I do not know the answer but I hear that rechargeable batteries are a bugger to dispose off !!

Azad Harripaul, Harlow, UK / Essex

Did I miss some math somewhere or something? The diesel driver states he used 49 liters. That's 12.94443 gallons. 545 miles at 12.9 gallons is 42.1 Mpg. That's less than the stated 48.1 Mpg from the prius. If they were just using the trip computers to calculate, versus actually using the fuel consumption, that's just a bad experiment.

Todd M, Indiana, USA

@Bob Wilson: The Prius has a CVT automatic transmission. So far as I'm aware this means it doesn't have a wasteful torque converter. There's no step changes in ratio to smooth out (the CV means Continuously Variable). In that case one can not claim an additional 5 mpg. Thus your assertion that one can not reasonably compare the automatic Prius to a car with manual transmission is absurd. Both the Prius and 520d are real cars available to the motoring public. The article suggests that if one drives any distance then by buying the BMW you'd be doing the world a favour.

Comparing the 520d with a Prius is absurd in that the former is a big saloon whilst the latter is a smallish hatch. However if the Prius is compared to, say, a Focus TDCi (a more like for like comparison in my view) then the hybrid con is more starkly revealed. A friend's Focus TDCi regularly achieves 60mpg.

Matthew Barratt, Maidstone, UK

Re: Bob Wilson

It should also be pointed out however, that the BMW driver used air con on this test and appears to have been driven in a somewhat more spirited manner. Also, the prius doesn't offer a manual transmission, which isn't bmw's fault, and even then the prius would only beat the 'normal' car by 3mpg -hardly a convincing victory. To be fair, the Prius was burdened with the weight of a rather hefty Cornishman :-)

Everything said and done it's amazing that the BMW lets a person achieve 50mpg without looking like a complete muppet, or eco nazi - as anyone inevitably does in a Prius.

winston lucas, Halifax,

Not a valid test because tester was not Progressive-thinking enough to fudge numbers for the greater good of Liberalism.

Tim, Manchester, USA

The comments above are dubious. Diesel fuel has much higher BTU content than gasoline. Gallons are not comparable.

The "automatic" in the Prius is a CVT, therefor no slippage. Therefore as good or better than manual transmission.

No way are particulates are going to cost that many deaths. These cars essentially put out no particulates.

The bladder is affected by how hot or cold the fuel is. Essentially, no difference.

By the way, I drive a Prius in Kansas. 38mpg in winter with cold batteries 10 degrees F, and 50mpg at 60 degrees F.
A 50 knot tailwind puts me at 60mpg at 70mph.

Ro Sylo, Kansas City, KS

What this really should come down to is this. WHAT VEHICLE DO YOU CHOOSE TO BUY? If you worry about mere humans affecting a planet's ecosystem then buy a ecobox. If you know better and rather would like to enjoy driving then buy an automobile.

Tim, Manchester, USA

As the arguements go back and forward no conclusion will ever be accepted. The most interresting point is that the Prius is a good car from which further developments can be made not retrograde eg Lexus. Yes the prius has flaws, the politicians should be pushing the development forward with benefits but carefully targetted. With regard to the BMW / et al of modern Diesels these are better all round cars but as is discussed each has its own merits Town versus A road driving. All manufactureres should be encouraged to develop better more efficient cars on the gorounds of wate etc. whatever the argument " Green" blue or otherwise as unecesssary waste of fuel - materials- food is criminal

Roy Stome, Edinburgh,

If the CO2 emissions are compared, the Prius comes out best as the carbon content of a gallon of diesel is greater than that of a gallon of petrol. Based on the official figures quoted in the article, a gallon of petrol gives rise to 10,996 g of CO2, and a gallon of diesel gives rise to 12,125 g. Thus on your test run, the Prius will have released 124.7 kg of CO2 whilst the BMW will have released 131.4 kg.

Dave, Oxon, OK

Come on everyone, the Prius maybe caught out in certain conditions ie motorway driving but it is not designed solely for high speed motorway driving , why not do a comparison now with the equivalent Lexus. Hybrid technology may not be the answer to everything but what has any other major manufacturer done other than Honda to at least try to provide an answer to enviromental issues facing the future of the automobile? The answer is nothing, absolutely zilch.

George McMillan, Ballyclare, Northern Ireland

Not a valid test as the BMW was manual transmission.

Harry Boswell, Melaka, Malaysia

There will be a lot of Prius owners in denial over this. The fact is that at best it's only as efficient as a diesel and the environmental costs of its manufacture are higher. Hats off to Toyota for selling this con to the tax man though.

John Carr, Colchester,

must be missing something.
why not a diesel electric car?
trains and boats have them.
by the way as a beemer owner, know which was the better drive!

john haydon rowe, javea,

The bladder on the Prius may explain the half gallon difference in fuel use, but the CVT is actually a more efficient transmission than the manual. And of course, the Prius is designed for congested driving more than highway driving.

Sam, Oxnard, CA, USA

There is an obvious conclusion that cannot be rebutted - if you drive mainly in cities and around towns and roundabouts with a great deal of stop/start then the Prius will be the most efficient car for your. Its technology is designed for that environment. However, on the open road a diesel is more efficient, so make a decision based on what your requirements are.

Having said that, let's see what comes out of the diesel-hybrid development schemes from the likes of Peugeot, that should move the technology on and maybe make 100mpg motoring a viable reality.

Kim, London, London

Hybrids work a lot better than this 'test' suggests. Most people spend most of their time in urban or semi-urban driving, when the hybrid gets a chance to recharge its battery.

Cruising at a constant speed will use little of the battery.
The Prius is efficient at low constant speeds (58 mpg at 50mph), but fuel consumption goes up markedly with speed, because of the tiny engine running at (inefficient) high revs. At 93 mph (150 kph) it can only do 29 mpg, compared to a BMW 535D touring which does 28 mpg at the same speed, or Golf 2.0 TDI (36mpg @ 93mph)

figures from http://www.autobild.de/artikel/der-auto-bild-verbrauchs-test_55631.html

John Spencer, London, England

Yawn, Yawn. You put the deep fried mars bar muncher in the Prius, and as everybody knows 60% of people live in cities, yet only 6% of this "test" was conducted in urban areas. This is British logic? Ny!

Boris Nikolayevich Grebe-Warbler, South East (Russia),

Interesting test, but out of curiosity, did you judge the final numbers by the fuel that went into the "tank" of each car?

It sounds from the onboard computers that the BMW was still winning, but one thing to be aware of with the Prius is that it has a bladder, not a tank, and this bladder's capacity is affected by how hot or cold it is. Air temperature and a warm engine after a long trip could change the capacity of the bladder, so it's difficult to say exactly how much fuel was used unless you trust the Prius' onboard computer.

Colin, Denver, CO, USA

The Prius has a fully automatic transmission but the BMW selected didn't have one. Take away the "5 mpg" attributed to the manual transmission and the results are reversed, significantly. This has been a pattern seen in every Prius vs Diesel report and sure enough, this article repeats an all too familiar pattern.

Bob Wilson, Huntsville, USA / Alabama

It was an interesting trial. However, even though the global warming contribution from the Prius was greater in the trail, reduced pollution in urban driving could still be saving many lives and greatly improving general health. If this is the case, the Prius still deserves the tax breaks.

In the year 2000 the estimated premature deaths from particulates in the UK was over 30,000 and traffic pollution has a contribution to play in this.

Peter Quill, Edinburgh, UK

All this says: Diesel engines are more efficient than petrol engines. Why hasn't Toyota put a Diesel in the Prius?, weight?. The only problem I have against having a diesel engine in my car is my wife, she doesn't like the smell of diesel fuel!

Ian Upton, Salta , Argentina

Since when did "green" people take any notice of the reality of motoring. This will change nothing.
The Prius has been declared "green" by the the experts of global warming, argue with them at your peril.

John Cooper, London,