Mercedes CLS 320 CDI

Its four doors and E-Class underpinnings suggest it has plenty in common with the firm’s executive and luxury saloons, but the coupé bodystyle hints at an affinity with the CLK and CL models.

In fact, you may ask why we didn’t test the 635d against the latter, given that they are both luxury two-doors. The reason is simple – not only is the Merc considerably bigger and more expensive, but there’s no diesel engine available, so it’s difficult to see it as a genuine rival.

Compared to Mercedes’ latest offerings, such as the C and S-Class, the CLS doesn’t quite fit in. But in terms of dramatic styling, there’s little that can rival it. It’s not as overtly sporting as the 6-Series, but its low-slung, curvy profile gives it a classic feel. The optional multi-spoke alloy wheels fitted to our test car are a letdown, though. They’re too fussy and at £1,530 aren’t cheap, either.

It’s difficult to find fault with the cabin, though. As with the rest of the car, the cockpit isn’t quite as driver focused as the BMW’s, but it’s extremely comfortable, thanks to the sumptuous chairs – although the driver’s seat could do with being mounted slightly lower.

The cabin has more character than the 6-Series’, and although some of the switchgear doesn’t feel quite as solid, the general build quality is top-notch. Passengers in the back will find it much easier to get on with, too.

Admittedly, rear access isn’t completely straightforward due to the low doors and roofline, but in terms of legroom and space, it’s way ahead of the 635d. For cross-continent trips, the CLS is ideal.

Indeed, comfort is the Merc’s forte. It feels superbly refined, and the same can be said of the 3.0-litre diesel engine. The powerplant loses out to the BMW in terms of power and torque, but its delivery is silky smooth. It couldn’t match its rival at the test track, although a 0-60mph time of 7.0 seconds is still quick, especially considering the car’s extra kerbweight, and in kickdown it proved just as rapid. However, the Merc will hit you in the pocket when it comes to fuel and tax bills.

On the open road, the CLS gains speed quickly and quietly, while the seven-speed auto offers immaculately slick changes – although if you want the optional paddleshifters, you’ll have to shell out an extra £190. The V6 does without the slight gruffness that occasionally spoils the BMW’s air of refinement, while its lack of power means it’s not as responsive on country lanes.

Similarly it lacks the agility of its rival, but that’s not to say the CLS isn’t sharp and composed. Body control could be better, but the steering offers decent feel and the ride is among the best we’ve experienced. That makes the Merc a superb cruiser and contributes to a relaxed feel that allows you to effortlessly cover hundreds of miles – not something that can be said of the 635d with its firmer suspension.

And compared to the BMW, the CLS is relatively good value for money. It undercuts its rival by a hefty £12,000, which leaves you plenty spare to spend on options. But then you’ll need it if you want a similar standard of kit to the 635d. However, even with £9,000 worth of options, including sat-nav, xenon headlights, leather upholstery and Keyless Go, our test car still worked out cheaper than the pricey 6-Series.

Details

Price: £43,957
Model tested: Mercedes CLS 320 CDI
Chart position: 1
WHY: It’s not strictly a coupé, but the CLS is a stylish cruiser, and although less powerful, the Merc is considerably cheaper.

Economy

A larger 80-litre tank ensures that even though the Merc was not as economical as the BMW, Returning 27.5mpg, it had the longer range at 484 miles between fill-ups.

Residuals

Judging by our valuations, the CLS is very Desirable. Over three years, it retains 56.6 per cent of its original price, which works out at £24,880.

Servicing

The CLS’s first three services will cost more at £710. Of greater concern is that the firm’s dealers came 18th out of 32 in our 2007 Driver Power satisfaction survey. BMW came 11th.

Tax

It may put out 32g/km more CO2 than its rival, but the CLS is slightly cheaper for business users. However, higher band owners will still be faced with a hefty £5,802 bill.