Mercedes CLS 350 CGI

In many ways, it was the Mercedes CLS that laid the groundwork for the X6. When it was launched in 2004, it introduced the world to the idea of a four-door coupé, leaving the way clear for rival BMW to go one step further with an SUV-based sports model.

So does that make the CLS old hat? Not a bit. Judging by the attention it draws out on the road, the Mercedes is as much of a head-turner today as it was when it first arrived in the UK.

A recent facelift has brought some subtle styling revisions. The grille has two bars instead of four, a range of new wheel designs has been added while the exhaust pipes now have a rectangular shape. Unless you’re a CLS aficionado, you probably won’t spot the differences.

Instead, your eye will be drawn by the low-slung front end and its distinctive lights, the rise and fall of the perfectly curved roofline and the drooping tail. It’s a majestic shape, and one that gained universal praise when lined up next to these rivals.

The X6 sets itself apart from the rest of the BMW range with a few cabin tweaks, but the CLS has a completely different dashboard to any other Mercedes. The flat facia and soft curves mirror the attractive exterior styling, while a new three-spoke steering wheel and white dials mean the CLS feels more special than the A5 or the Cayenne.

In the back, the Mercedes steals a march over its two-door Audi rival. As with the X6, it has easily accessible seating for four. The downside of the sleek roofline is that passengers over six feet tall will have to slouch to get comfortable, although the leather seats are luxurious.

The revised CLS range has four engine options – all mated to Mercedes’ seven-speed automatic transmission. Alongside the V6 CGI model tested here, buyers have the choice of 5.5-litre and 6.3-litre V8 petrol units, or a 3.0-litre V6 diesel.

The Charge-stratified Gasoline Injection (CGI) powerplant is brand new, and delivers 288bhp; that’s 20bhp more than its predecessor. Also, the advanced engine also increases economy by 10 per cent when running on sulphur-free fuel – a petrol standard that’s set to become more common on garage forecourts.

Benefiting from cutting-edge direct injection, the CLS has diesel-like thrust and petrol levels of refinement. The engine is whisper quiet and never feels underpowered, although this wasn’t evident at the test track. In the 0-60mph sprint, the Merc was slower than all its rivals bar the X6, with a time of 6.7 seconds. This is partly due to the seven-speed auto, which makes the car slower off the line; the trade-off is that the box is great at maximising the V6’s 365Nm of torque at speed.

In the real world, you’ll wonder why you would ever need to opt for a more powerful CLS variant, but tackle a corner, and all becomes clear. Air-suspension is standard on the V8 models, and it’s sorely missed on this entry-level car. With conventional dampers, the Mercedes pitches and rolls more than its BMW and Audi rivals, so fails to inspire confidence.

The steering also seems to suffer more numbness the faster you go. A soft brake pedal only adds to the sense that this CLS is more of a cruiser than a performance saloon.

At £46,995, the Mercedes costs more than all except the Porsche here. Standard equipment is generous, but as the 350 CGI needs the £1,295 optional air-suspension to polish its dynamics, you could be left feeling short-changed.