Road Test: Mercedes-Benz C Class C250 CDI AMG Sport 2dr Auto

Explaining the all-new C-Class Coupe's place in Mercedes history takes a bit of work. Merc doesn't - ardently doesn't - want you to think of it as the new CLC. That clunker, launched in 2008, was a parts-bin update of the decade-old C-Class Sports Coupe, a poor man's rival to the 1-Series. The new C-Class Coupe is bigger, more expensive, and a genuine two-door coupe rather than a three-door hatch.

So it's not the new CLC. The new CLK? Closer, but not quite. The CLK was more or less replaced by last year's larger, pricier E-Class Coupe. If you've got bootlid letters swimming before your eyes right now, you're not alone.

However, step back from Merc's tortuous product history, and the C-Class Coupe is absurdly simple. It's the two-door version of the C-Class. It's a straight-down-the-line competitor to BMW's 3-Series coupe and the Audi A5.

Maybe this is sensible thinking from Mercedes-Benz: BMW shifted nearly 6,000 3-Series Coupes last year; the A5 has been a fat sales success for Audi. However, by squaring straight up to the two instead of shuffling in the gaps, the C-Coupe has nowhere to hide. Do it right, or take a beating.

No surprise, then, that Merc has made a thorough job of this conversion. The coupe may share a platform and engines with the C-Class saloon, but only one body panel is carried over: the bonnet. The rest of the metal is new: the coupe's roofline is four centimetres lower than that of the saloon, the windscreen raked back more steeply.

Like the 3-Series and A5, the C-Class Coupe is a strict four-seater. There's no occasional middle rear seat here, just a plastic compartment between the two rear chairs. The rear backrests can split and fold down for extra bootspace, which might explain why Merc has eschewed the CLS-style raised centre stack between the back seat passengers. More difficult to explain why there's no fold-out armrest there.

There's just enough room for one six-footer to sit behind another, though the back-seat passenger's head will graze the roof lining if sat up straight. It's plenty comfy for medium-length journeys and, as with all current Mercs, the build quality feels pyramid-spec.

So far, so not-very surprising. But move from the rear to the front of the C-Class Coupe, and the Mercedes starts to differentiate itself from its sworn enemies.

The set menu comprises three petrols - two 1.8-litre turbo fours producing 154bhp and 201bhp, and the 302bhp six-cylinder C350 - and two diesels. We drove the C250 CDI, the more powerful of the pair. It's a four-cylinder turbo that produces 201bhp and an umami-flavoured 368lb ft of torque, while returning 58mpg and emitting only 128g/km of CO2. That's a stunning set of statistics: good enough to eclipse its BMW rival, the six-cylinder 325d, which is not only thirstier and less clean than the Merc, but generates less power and torque. Bettering BMW in a power/efficiency trade-off is like out-negotiating Bernie Ecclestone.

It's a serene engine. Where the BMW six encourages you to wring it out, the Merc four gently mooches around the bottom end of the rev range, the optional seven-speed auto shifting up early when left to its own devices.

Don't think it's slow, mind. Far from it. The C250 will crack 62mph in seven seconds, its mid-range torque spiriting you past dawdling tractors with nothing more than a feathery whoosh. But the drivetrain combination doesn't encourage you to get stuck in; no, it deals with requests for quick downshifts with a mixture of hesitation and outright contempt. In most everyday driving, you'll leave the gearbox and engine to do their own slow dance, delivering the power in great wafting low-end lumps.

Such is the C-Coupe driving feel. Against the 3-Series and A5, this ploughs a more tranquil furrow: not floppy, not squidgy, but tranquil. The steering trades in a few degrees of pointiness for motorway-devouring ease, and even on 18-inch wheels - all C-Coupes coming to the UK will get the big rims and the AMG styling kit - the ride is relaxed, soaking up the road effortlessly. Unless you're cresting the ton across a recently ploughed potato field, wind- and road-noise are essentially non-existent.

Despite an ‘amplitude dependent' damping system, which automatically adjusts the compliancy of the shock absorbers for a stiffer ride when it senses the red mist descending, the C-Coupe isn't transformed into a spiky weapon on B-roads. Dynamically, everything is present and correct - body roll is minimal, and the chassis is strong - it's simply that, as in most of the current Merc crop, the relationship between driver and road is tempered a little. This isn't dynamic compromise, but a more chilled philosophy.

Some might say that, by not making the C-Coupe more overtly sporty, Merc has missed a trick: buyers wanting a softer experience will opt for the similarly priced saloon instead. Coupe drivers, for the most part, eschew a bit of practicality for a sharper set-up. But surely the world already has enough smart coupes that foist a crunching set-up upon drivers who would rank ‘full-bore Nürburgring assault' just below ‘hacking off own genitals' on a list of enjoyable ways to spend a weekend? Mercedes believes its clientele to be a somewhat more sanguine bunch.

If you want your C-Class Coupe with proper sporting intent, you'll have to hang on until the AMG version arrives. With the C-Coupe, that wait is about as long as it takes you to click a link. Press this highlighted bit to see how the two-door C stacks up with a V8 crammed under the bonnet...