Big ones, little ones, fast ones, slow ones. I don’t really care what a car’s like so long as it does the job it has been designed for better than anything that has gone before. I still get genuinely excited every time I think I’m about to drive a ground-breaking car and really cheesed off if it then lets me down.

But of all the different cars I drive each year, and it’s a three-figure sum, there will never be more than a handful I would actually want to own. Yet staggeringly, two of this year’s cars have been Mercedes.

I’m surprised because a) no car company has ever got two onto my list of personal favourites before; and b) because the same company

that came up with the underachieving, overpriced B-class has also produced two of the best cars of the year.

The first is the new R-class, a car that seemingly answers every question a wealthy family could ever ask and probably quite a few they haven’t thought of yet. It’s a genuine luxury car, with the space and flexibility of an MPV but without the visual stigma, and all the muddy field and snowy slope off-road ability most owners will ever need.

The second doesn’t look new at all. It’s a C-class whose basic shape has been with us for more than five years. Indeed you need to look under the bonnet of this one to see where the stardust has been sprinkled.

For during the past five years motoring journalists have bemoaned the fact that Mercedes’ big, six-cylinder diesel has not fitted under the bonnet of the C-class, leaving its most powerful oil-burning offering as the five-cylinder 2.7 litre C 270 CDI which, bluntly, couldn’t hold a candle to the six-cylinder diesels used by BMW. But now Mercedes has binned the old five-cylinder engine and replaced it with a new 3 litre motor, whose cylinders are arranged in a V formation rather than in one long, space-consuming line.

The result is that a car I had come to ignore as being over the hill has been given a new lease of life. This is as welcome as it is surprising.

Consider this for a second. Although it’s called the C 320 CDI, it actually uses a 3 litre engine similar in capacity to that of the equally inaccurately named C 280 petrol C-class. There’s not much between them in their power outputs — the diesel has 224bhp, just 7bhp less than the petrol — but when you accelerate it’s not power you feel: it’s torque. And while the C 280 has 221 lb ft of the stuff, its diesel sister has a simply ridiculous 376 lb ft.

So while its outright acceleration figures point to a 0-62mph time of “only” 6.9sec, this does not reflect how cars are used in the real world. In the real world you want to be able to accelerate from the urban speed limit to the motorway speed limit, and according to my fag packet calculations it can do this in less than six seconds, which puts this square old saloon’s performance squarely in the Porsche Boxster bracket. Interestingly, Mercedes doesn’t release comparable figures for its range-topping AMG-powered C 55, but given that it has the same torque yet needs 4000rpm rather than 1600rpm before it can deliver it, perhaps it thought this was information best left out of the public domain.

However, if this car’s sole appeal were its performance, it would hardly be enough to set me vainly searching for ways to accommodate one in my life. More attractive still is the sheer nonchalance with which it is delivered. This is a fantastically refined car, even by the heady standards of modern diesels, and when it’s dark and wet — which it seems to be almost all the time at the moment — it will put away the outrageous side of its nature and whisk you about on a whiff of throttle while appearing to use no fuel at all. Mercedes says it will return an average of 37.2mpg, but on a gentle wander to Wales and back it stretched every gallon over 40 miles.

And it made me remember all those other C-class strengths that you tend to forget as other more modern machines compete for this space. Like its creamy ride comfort, excellent refinement and its ageing but still high-class interior.

It also does precious little to annoy you — yes, it would be better with some more rear leg room and the overall shape of the car is hardly cutting edge, but compared with its stiffest rival, the new BMW 330d SE, it’s a positive beauty.

So if you like life made easy but never dull, if you value high performance but need to keep an eye on the fuel bills and, above all, if you thought a small diesel Mercedes saloon could only ever be driven by reps or retired gentlemen wearing hats, the C 320 CDI is here to tell you different. It may be five years late but, believe me, it’s been worth the wait.

VITAL STATISTICS

Model Mercedes-Benz C 320 CDI
Engine type 2987cc, six cylinders in a V
Power/Torque 224bhp @ 3800rpm / 376 lb ft @ 1600rpm
Transmission Seven-speed automatic
Fuel/CO2 37.2mpg (combined cycle) / 201g/km
Performance 0-62mph: 6.9sec / Top speed: 155mph (electronically limited)
Price £31,045
Verdict The understatement of the year
Rating 4/5

THE OPPOSITION

Model BMW 330d SE automatic £30,880
For Incredible blend of performance and economy
Against Only those awkward looks

Model Audi A4 3.0 TDI quattro tiptronic £28,425
For Great looks and build quality
Against Not as fast or as frugal as its best rivals