In isolation, the figures for the 300C don’t look unimpressive. A 0-60mph time of 7.3sec is the sort of speed that will get you out of trouble in most situations. Accelerate at the start of a slip road and 7.5sec later you’ll be at the legal limit, too. Looks like it does the job, doesn’t it?
Well, look around the market and the 300C’s figures don’t look quite so convincing. The 236bhp it develops on overboost (for 90sec, which makes it barely worth mentioning the ‘standard’ 221bhp) is some way short of the 260bhp or so offered by the BMW 530d and Mercedes-Benz E350 CDI, both of which can be had for under £40k.
They can hit 62mph in a claimed 6.1 and 6.2sec respectively, return up to 53.3mpg on the combined cycle and have CO2 emissions as low as 139g/km. The 300C, meanwhile, has a combined economy figure of only 39.2mpg, for which its five-speed automatic gearbox doubtless does it few favours.
Still, it is a relatively refined unit. Our noise meter was away being calibrated when we tested the 300C, but at idle it emits a muted rumble that becomes little more vocal as speeds and revs rise. Because of the limited number of ratios, there’s a bigger drop or rise in revs than in most rivals when you change gears but shifts are smooth enough.