Pretty refined. On start-up and at idle, there are no serious hints of what kind of fuel is being burnt up front. There's no real clatter and few vibrations get through to the driver, proving that Mercedes has worked hard on soundproofing materials.
The manual gearbox is pleasant to use, with a light action and fairly precise shift. The engine feels willing, but it's not really in the same league as the 2.1-litre unit in the C 220 Bluetec for pace, making the car feel slower than it should. At low revs there's a bit of a flat spot – but maximum torque is available from as low as 1500rpm, so as long as you keep it spinning in its sweet spot, you'll be able to keep up with other traffic without too much trouble.
There are five different driving modes, offering the driver the choice between Eco, Comfort, Sport, Sport+ and Individual. In each position, four parameters are changed, namely the throttle response, steering effort, air conditioning power and start-stop system. In automatic models, the shift points are tailored to each mode too. In Sport and Sport+ modes, the engine management matches the revs with each downshift, an entertaining – if somewhat pointless – feature on such a frugal, economy-minded diesel.
The limiter cuts in at at 5200rpm, but you'll rarely want to push it that hard, as there are no real gains in peformance at high revs and refinement suffers as the engine strains at these higher speeds. We reached 47mpg in city driving, a bit far from the official figure, but a light-footed approach would soon see that figure rise towards 60mpg.
On the motorway where these cars spend most of their time, the 114bhp engine starts to show its limitations. At higher speeds it needs to work harder and becomes more intrusive, and overtaking moves need to be planned quite far in advance, unlike in the punchier large-capacity diesels in the range.
Grip is decent, even in damp conditions, and the ride on 17-inch alloy wheels and comfort suspension afford a reasonably composed ride, but low-speed bumps and ridges in town will still catch the C-class out and the steering is never quite as faithful or direct as in rivals like the BMW 316d, which is a bit noisier, perhaps, but a much sharper thing.