We’ve been impressed with the A200 CDI’s 134bhp 1.8-litre diesel showing in the B-class. The lighter, aerodynamically slimmer A-class, equipped with the quick-shifting 7G-DCT dual-clutch automatic gearbox, cracks 60mph in 8.9sec rather than 9.4sec; it finds its way to 100mph marginally quicker, too. Significantly, the shorter sprint time puts it on a par not only with the 143bhp BMW 118d but also the Audi A3 2.0 TDI.
However, draw the comparison out to 100mph and the Mercedes lags almost 2.5sec behind its closest rival. The issue here, as before, is a subtle lack of potency. A 221lb ft torque peak versus 236lb ft for the Audi and BMW may sound like an insignificant deficiency, but its imprint is felt as a faint paucity across the range. It will not upset most drivers, but it downgrades the enjoyment of pushing on – which is unfortunate given that the chassis tune positively encourages such behaviour.
Find the patience to settle down and the motor reveals its dividends. We recorded a respectable 57.6mpg touring route figure, and with the engine’s revs quick to settle into the long stride of the gearbox’s seventh ratio, that kind of economy isn’t unusual even on more varied runs if you deliberately eke it out.
If economy is of particular concern, the 109bhp A180 CDI performs admirably, with CO2 emissions as low as 99g/km and combined fuel economy of 74.3mpg. That it takes 11.3 seconds to reach 62mph is the only real penalty.
For ultimate peace and quiet, look to the impressive petrol engine line-up. The range-topping A250 develops 211bhp, endowing the A-Class with hot-hatch levels of performance and managing a 0-62mph sprint in 6.6 seconds. But while it sounds good on paper, the engine fails to electrify proceedings like a range-topping petrol powerplant arguably should. It is responsive, leggy, refined and swift - but then so is the 168bhp diesel-engined A220 CDI beneath it that tops the diesel side of the line-up.
Lower down the petrol range, the 156bhp A200 manages the 0-62mph dash in 8.3 seconds, with the entry level 122bhp A180 taking a second longer. The A180’s engine is no masterstroke, but it does the important things quite well. It stays quiet at low revs, pulls obligingly in high gears, and returns decent economy. This isn’t a fast car, but it’s a flexible one, with a usable low and mid-range.
The A-class range would be better if it were capable of being seen and not heard. Unfortunately, the combination of intrusive induction noise and mechanical thrashing blights the A-class’s cabin in much the same way as it did in the B-class, particularly on the diesel front.