Ugly Betty just got interesting

Imagine a car with more power than the most powerful Lotus Elise, with better acceleration and a higher top speed than the latest VW Golf GTI. Now imagine that same car using less fuel than the smallest-engined Ford Fiesta, while also emitting less CO2. That would seem straight out of science fiction.

But it’s not: the car exists and is in your local BMW showroom right now. It’s the 123d, I’ve just driven it and it’s every bit as incredible as its statistics suggest. So this is perhaps a strange time to restate my long-held feelings of hostility towards the BMW 1-series.

Over the years, while colleagues have cooed over BMW’s smallest mainstream product, I’ve only seen a car as ugly as it is poorly packaged. Overpriced, cramped, not even that great to drive . . . I’ve struggled to see its worth.

But the 123d, or to be specific, this 123d, is different, and not just because of the new and quite extraordinary power plant under the bonnet. While the engine is available in the standard hatchback, BMW introduced me to it in the brand new two-door coupé that goes on sale next month. And that changes everything.

For while a 1-series hatchback has very little rear room, by the lower level of expectation we have of coupés, the two-door’s space is perfectly acceptable. Second, while it’s no Alfa Brera to look at, the coupé is a sight more elegant and attractive than its misshapen five-door sister.

Thus my two most serious complaints of the 1-series dissipate – leaving only the price to ponder. For now, though, let’s consider the figures. Ten years ago 100bhp was a very respectable output for a diesel engine of this size. But today’s 123d provides 204bhp, making it by far the most powerful 2 litre diesel ever to be offered for sale. Remember Ford’s mad, winged monster of 20 years ago – the Sierra Cosworth? At the time it was thought of as a barely controllable supercar, a thinly disguised racing machine wearing numberplates. Yet it produced the same horsepower as this 123d.

While this means the 123d will accelerate to 62mph in 7sec and not stop until it’s doing a fraction under 150mph, the figure that really looks like a misprint is the one relating to fuel consumption. You might be impressed if a car of this potential could do 35mpg. But I thrashed a 123d all morning and failed to use that much fuel. The official combined-cycle figure is 54.3mpg, so even with the coupé’s pathetic 11½gallon fuel tank, that’s potentially more than 600 miles of travel without stopping.

Being inherently suspicious of anything that appears too good to be true, I suspected the price for squeezing so much power from such a small engine would be that it would rattle like a one-year-old’s birthday party. And if you stand outside the car with the engine at idle, its sound is indeed loud and distinctly dieselly. But on board you hear almost nothing. It revs with a willingness I’ve not previously experienced in any diesel, and when you put your foot down, it responds like a large petrol engine, not a little diesel.

Unsurprisingly, BMW is marketing the coupé version of the 1-series as the most sporting of the breed, and when fitted with M-Sport suspension it’s remarkably quick. It is spoilt only by the electrically assisted steering, which lacks the sense of connection to the road that you tend to find in a conventional hydraulic steering system. Another demerit is the overly firm ride. Were it my money, I’d save myself £1,435 and buy the standard 123d with normal suspension because it’s prettier and doesn’t look like a refugee from an auto accessory catalogue.

That means the cheapest 123d coupé still costs £24,855 before you add extras such as the sat nav and leather upholstery that many will regard essential and will drive the price up to almost £30,000. Nonetheless, in the microscopic class of compact, high-performance diesel coupés, the 123d reigns supreme.

Which leaves just one question: if this engine works that well in a 1-series, what could it do for BMW’s other, considerably more likeable models?

Vital statistics

Model BMW 123d M Sport Coupé

Engine type 1995cc, four cylinders, twin turbo

Power/Torque 204bhp @ 4400rpm / 295 lb ft @ 2000rpm

Transmission Six-speed manual

Fuel/CO2 54.3mpg / 138g/km

Performance 0-62mph: 7.0sec / Top speed: 148mph

Price £26,290

Verdict An exceptional engine in a fair car

Date of release November

The opposition Model

Alfa Romeo Brera 2.4 JTDM SV £26,995

For Wonderful looks, smooth five-cylinder engine

Against Thirsty for a diesel, cramped rear cabin

Model Audi TT 2.0 TFSI £24,900

For Beautifully built, wonderful cabin, good value

Against Useless rear seats, no diesel option