It is a sign both of the times in which we live and the raw potential of this new BMW 335i Coupé that the pre-drive briefing at the car’s launch in Innsbruck was conducted not by some BMW big cheese but the police. The Austrian constabulary were keen not to spend the afternoon digging us out of the Tyrolean scenery and were not shy about saying so.

You may think this says more about British motoring journalists than anything we were about to drive but our assessment-to-accident ratio is actually rather good. Even so, they did refer darkly to an “earlier incident”, and I suspect it was thoughts of what happens when a 306bhp, rear-drive BMW meets a throttle-happy hack on a streaming wet mountain road that had them appealing to us to behave.

They need not have worried. Now that the M3 is out of production the 335i takes over the mantle of fastest 3-series, but even on the treacherous roads that BMW selected, not once did it give cause for concern.

We were here not only to try BMW’s new twin-turbo 3 litre engine but also the 3-series’ third body style, after the Saloon and Touring shapes. I care little for the new coupé’s styling. Having been so adventurous in the styling of cars like the 5, 6 and 7-series (and walked into a storm of criticism), BMW has tried to be conservative and ended up being bland. There is some sense of purpose about the front, but the side is oddly proportioned and the back verging on the insipid.

But there’s nothing dull about what’s under the bonnet. BMW hates turbocharged petrol engines so much that it has only ever made two, and none in the past 20 years. As it has been quick to say when asked about rivals’ engines, turbos kill throttle response and guzzle fuel.

Now, however, BMW has embraced the turbocharger like a long-lost son. By marrying a new form of direct fuel injection to two small, low-pressure turbos, the theory is you get the power and torque for which turbo motors are famous without the drawbacks.

And so it proves. You would never twig this engine was turbocharged. It offers maximum torque at just 1300rpm and when you hit the accelerator it responds at once. It can hit 62mph from rest in 5.5sec on its way to a restricted 155mph top speed, and BMW’s boffins say that in the real world it is as quick as the M3. Yet you can still expect it to return 30mpg on a quiet run. Which is more than you’ll be able to say about next year’s new V8-powered M3, which will have at least another 100bhp.

And this engine’s been married to a chassis of near equal ability. So long as you don’t opt for BMW’s awful active steering system the 335i handles brilliantly. BMW knows that making you feel at home at the wheel is achieved only when, through the feel imparted by the steering and chassis, the driver is kept fully informed of conditions underfoot. It does this superbly, though the price you pay is an exceedingly firm ride.

It’s worth it. The 335i’s showroom qualities are strong, too. Unlike coupés such as the Alfa Romeo Brera and new Audi TT, the 335i offers adequate space for four adults, so can be used as a family car. Its only true rival is the Mercedes-Benz CLK, but to get a Merc with similar power will cost £46,740. The 335i Coupé is priced at £33,420.

Should you buy one? Probably not. While the 335i Coupé is tempting, there’s another 3 litre twin-turbo model that’s likely to be even more compelling just around the corner. The 335d is powered by the same 286bhp diesel engine that gives the larger 535d such outrageous performance, but because it’s being installed in the smaller, lighter 3-series body, it’s going to be even faster and more frugal — hitting 62mph just 0.6sec after its petrol-powered brother, but returning 37.2mpg in the combined cycle. And with even more torque, in the real world it’s going to feel faster still. And it should cost little or no more than the car you see here.

The true beauty of the 335i Coupé is found not in its awkward appearance, but in the depth of engineering excellence beneath the surface. It might not be much to look at, but to drive it is little less than gorgeous.

THE OPPOSITION

Model Mercedes-Benz CLK 500 £46,740
For Smooth and characterful V8, excellent ride quality
Against Dull appearance, should be more fun to drive

Model Alfa Romeo Brera 3.2 JTS V6 Q4 SV £29,850
For Looks great from some angles, high quality interior
Against Not sufficiently fast or fun to drive, joke rear seats