What is it?
If you buy a new Mercedes C-class from launch, this is the finest model Stuttgart can offer – the new six-cylinder, petrol powered C350 Sport. Until the AMG C-class appears in September, it must carry the mantle of the most sporting, powerful C-class and with it the hopes of Mercedes that it can attract a younger, more dynamic constituency of punter into its new and conspicuously attractive small saloon.

What's it like?
Heavier and less powerful than its closest rival, the BMW 335i, the C350's performance is unexceptional. Mercedes reckons its 272bhp, 3.5-litre motor will propel it to 62mph from rest in 6.4sec but to me it simply didn’t feel that fleet. Moreover, if you really start rummaging around in the upper reaches of its rev range, the V6 starts to sound a little hoarse and strained.

Left in the mid-range, however, and it fares much better. This is an engine that hits a peak torque figure of 258lb ft at just 2400rpm and maintains it all the way to 5000rpm, so the way to drive it is to select a higher gear than you might naturally choose, and let the engine rather than the gearbox do the work. Besides, left to its own devices the seven-speed auto is as trigger-happy as ever when applied to this engine and only really calms down when bolted to the back of the 3.0-litre diesel motor.

But once you’ve learned to lock it in a gear and drive on the engine’s torque rather than its power, there is a great deal to be enjoyed here. This way you relegate the powertrain to a support role for a chassis of exceptional quality for this kind of car.

On a decent road you notice at once how much better balanced it is than the diesel C320 CDi and it is only on further investigation that you discover the C350 is a whopping 90kg lighter than the diesel. It turns in sharply, resists understeer determinedly and allows your hands to position the nose and your right foot to do the same for the tail. It seems odd to be saying this about a C-class, but it is a precision instrument, which combines fine body control with still enviable ride quality.

All of this only adds to the sense of well-being created by the C-class’s attractive shape, sensibly proportioned interior, perceived standard of build and quite exceptional high speed refinement.

Should I buy one?
It’s a shame the engine is not a little more accomplished, for in most other respects the C350 is all you could hope for from a small Mercedes saloon: compact yet classy, comfortable yet capable all at the same time.

There is no doubt that the 335i, with more firepower at its disposal and a more aggressive set up, is the more focussed driver’s car and, I don’t doubt, the car most of us would choose to pedal if offered the keys to both. But as a thing to live with day to day, the C350 is actually the more broadly appealing car.

Andrew Frankel