Mercedes C320 CDI A'garde SE Est.

We got behind the wheel of the estate model, which is the first car to receive the new powerplant. The mildly facelifted CLK and E-Class will follow, before the unit is fitted to the next- generation S-Class. Using the latest fuel-injection technology, the engine meets current Euro IV emissions rules even without a particulate filter. With one, it complies with strict future regulations. Despite the green credentials, its 224bhp and 510Nm of torque deliver blistering in-gear pace and a 7.1-second 0-60mph time. Maximum torque is available from just 1,600rpm.

And it is not only blasting away from the lights where the newcomer scores highly. Thanks in part to the well suited 7G-Tronic seven-speed auto gearbox, motorway speeds are accomplished with remarkable ease and refinement. There is always performance in reserve, too - as you would expect from a car with a 150mph maximum speed.

An Avantgarde estate model like ours will set you back ΂£31,970 - but start adding optional extras and this soon rises. Leather upholstery at ΂£1,250 and heated front seats for a further ΂£310 are just two of the features most buyers will be looking for.

Customers can also opt for a pair of gearshift buttons mounted on the back of the steering wheel to change manually between the ratios. These increase the diesel's already broad appeal.