2021 Mercedes C-Class review: Merc should go the extra mile

The clatter of a cold diesel brings a smile to Andrew Frankel
2021 Mercedes C Class on the road

A smooth Mercedes straight six might have been preferable to this 2-litre four

It is a sign of the times, and how rapidly they are changing, that I was momentarily surprised by the sound made by this all new Mercedes C-Class upon start up. And it wasn’t just the quality or quantity of the noise emanating from under its bonnet, but the fact it was making one at all.

For here at the coalface of new car assessment, almost everything that turns up these days is electric, or a petrol-electric plug-in, which means the only way you know they’re ready for action is that their dashboards light up like Christmas trees. But what I was hearing was the ugly rattle of a cold diesel engine overcoming massive internal resistance to compress its mixture sufficiently to make it spontaneously ignite. I quite liked it.

And those of us of a somewhat traditional bent should take a long hard look at this car: a traditional saloon from the world’s oldest car manufacturer powered by what was once the most popular fuel in the land or on the continent. It’s not just its power source that is in a state of decline. Conventional four-door cars are yesterday’s news too, as the world continues its love-in with heavier, slower, more polluting and less fun crossover SUVs.

So this is something of a last laugh. The next generation C-Class is seven years away by which stage Mercedes-Benz will likely have stopped even building diesel engines, let alone installing them in brand new cars; if, indeed, there is a new C-Class in seven years’ time.

If not, is a nameplate that’s in its 30th year going out with a roar or a whimper? On this evidence I’d call it a muted growl.

2021 Mercedes C Class interior

Screen-tapping and voice commands are the modern Mercedes environment, although this is fairly simple to use

There is plenty to like. Predictably the C-Class is longer, wider and heavier than ever, but the latter can be excused at least in part to the fitment of a 48-volt mild hybrid drive to every model, there to help fill in the holes in the torque curve and to make the official consumption and CO2 figures look better than they probably are. But the car is pleasantly styled outside and extremely luxurious within.

As is the modern way, it has abandoned expensive switches and buttons that need to be individually engineered and homologated in favour of an enormous central flat screen you must prod with your fingers. The dials are also a screen, operated by haptic controls on the steering wheel. Or you can just use your voice, though shouting, “Can’t I just have a bloody button?” at it is a thankless, fruitless task. And, to be fair, if you do have to go down this road, the Mercedes approach is as good as any I’ve seen to date. It’s easy to operate and appears to have been designed by people who think like you and me with the result that the first time you attempt any new command, more often than not it does what you want.

So far so fine. Its biggest problem is that diesel engine, which when it goes is one whose passing I’ll lament less than most. Mercedes has often had a problem engineering the level of refinement expected of the three-pointed star into its smaller diesels, and this car is no exception. At the entry level to the range its quite loud and coarse voice would be far more acceptable and expected even, but this 300d is the flagship, and for a saloon costing over £50,000 it’s not good enough.

Of course in times gone by Mercedes would have solved this problem by fitting one of its delightfully smooth straight-six diesel engines to the car and I’d likely be singing its praises but it would cost a little more to run and probably a lot more to tax so that was never going to happen. So instead of a 3-litre six, there’s a highly stressed 2-litre four which, with a modest boost from the hybrid develops 261bhp which is enough to provide the C300d with convincing performance.

2021 Mercedes C Class rear

But the ride is not quite right either. Such is the peculiar direction in which progress travels these days, with this all new C-Class you can’t even option in either air springs or even adaptive dampers and in this case it proves emphatically that less really is less. It’s not that the car rides poorly – it doesn’t, it rides perfectly adequately – but it no longer rides superbly, something that could be said of every previous generation. In an instant, the one key strength it always held of its nemesis, the BMW 3 Series, has gone. Which is a shame.

Happily, it still handles better than you might expect of a cooking Mercedes saloon not given the AMG treatment, and coupled with the engine’s strong performance, Merc’s always excellent nine-speed automatic gearbox and the retention of rear-wheel drive, the C-Class still provides entertaining company on the right road, something said with increasing rarity given the rising prevalence of high and heavy electric machines.

Even so the new C-Class, though a decent car, is one I wanted to like far more than I did. That sense of indulgent over-engineering that Mercedes always used to have, lost in the 1990s and recovered in recent years, seems to have slipped just a little here. All car manufacturers are having their strings pulled tighter than ever as they struggle to design, engineer and make profitable an entire new kind of car so perhaps this somewhat pulled punch is understandable. But I always expect a Mercedes to go above and beyond. So when you find one that instead stops dead at ‘enough’, it’s always going to be mildly disappointing.

2021 Mercedes C300D AMG Line Premium Plus statistics

Price £52,125
Engine 2 litres, four cylinders, turbo diesel, mild hybrid
Power 261bhp at 4200 rpm
Torque 406lb ft at 1800rpm
Weight 1775kg
Power to weight 147bhp per tonne
Transmission Nine-speed automatic, rear-wheel drive
0-62mph 5.7sec
Top speed 155mph
Economy 55.4mpg
CO2 139g/km
Verdict Good enough and no more