German hybrid saloon showdown: Mercedes C300e vs BMW 330e

Big claim. How so? Well, this is more than just a quick face-off to see if the new Mercedes C-Class is better to drive and nicer to be inside than the best medium-sized premium saloon car you can get: the BMW 3 Series. And I’ll not bother with faux suspense: it isn’t. We’ll come to the reasons why the BMW is still the traditional German saloon of choice in a minute, though. 

Because it’s the versions of the new C-Class and 3 Series present that form the main plot thread. They’re the plug-in hybrids, or PHEVs if you prefer. The new Mercedes-Benz C300e, and the BMW 330e. Both in bodykitted AMG-line and M Sport trim. Both cost around £45,000. Both have around 300 horsepower and can whisk you from 0-60 in about six seconds.

Photography: Johnny Fleetwood

And – crucially in the land of the aspirational company car, where diesel for so long reigned unassailably supreme – they’re both phenomenally cheap to tax. Cynics will head for the comments section right now, frothing that PHEVs are only bought to dodge the Exchequer, with no intention of ever being charged up for the good of the planet.

The Mercedes could be the car to change your mind – and to change how you use your car. While the BMW 330e makes do with a claimed 37 miles of electric-only range (more like 28 miles on this particular miserable English winter’s day) the C300e is good for a monstrous claim of 68 miles. Yep, into triple figures in Euro-speak – it’s a 100km+ PHEV. Woah. Even today, with the heater cranked up and no time to spare as I peel onto a fast-flowing section of the M4 motorway, it’s reporting a 51-mile range before the 2.0-litre petrol engine’s lie-in is interrupted. 

Now, you could argue that with so much e-range, the C300e has tripped over into pointlessness. Why not just buy a proper EV and have done with it? Nice idea, but if you think that, you’re already sold on electric cars. You’re the choir. There’s a heck of a lot of people out there who are still sceptical. Still unsure. Offering them a classy, well-made, swift German junior exec that’ll do the British average (pre-pandemic) 23-mile commute on pure electric and only need a recharge every other day makes the C300 incredibly compelling. 

Such prodigious range is thanks to a 25.4kWh battery. As observed by our Paul Horrell in his early first drive of the car, that’s more cells than a whole Mk1 Nissan Leaf. To this, the BMW only has 12kWh in reply. So there’s nothing especially innovative about the Benz – it’s not cracked the code and found a loophole in battery chemistry. It’s just got a really, really big battery. 

As a result, Mercedes has had to make certain compromises to fit it into a C-Class, even though the C is now as big as an E used to be. Rear legroom is notably less generous than the 3 Series offers, while a 315 litre boot is easily beaten by the BMW’s 375 litres. 

The BMW is also lighter. It weighs 1,740kg, which seems like a lot for a 3 Series, until you spot the C300e is the wrong side of two tonnes. And that’s why despite having more combined power than the 330e (312bhp plays 289bhp), it’s a few tenths slower from 0-62mph on paper.

On the road, where cars actually live, it doesn’t feel slower, so you won’t care. Here’s why. Whereas BMW has pursued a typically sporty sensation for its hybrid Three, Mercedes has sensibly recognised that the C-Class needs to do something different. Chase ultimate driving dynamics and it’s likely to come off second best. 

Relax, and it can carve a wafty hybrid niche. So it does. Whereas the BMW’s engine growls menacingly and revs crisply, the Mercedes remains unflustered and polite. The 330e wants you to know its engine is working, and enjoy that fact. The C330e would rather you didn’t. For the most part, you might forget it has a petrol engine at all, while the 129bhp e-motor does all the pushing. 

Within half an hour of driving these two back to back, the BMW is all out of juice. The Mercedes still has 40-odd miles of kilowatts left. So while the average fuel economy in the white car plummets from ‘infinite’ to settle around 43mpg, the C-Class goes on without burning fuel. And on. And on. Result? As we sploshed home, the finally exhausted C-Class reported 78 miles per gallon. 

Twice the battery, twice the range, twice the fuel economy. I’m rubbish at maths, but those numbers are fairly easy to grasp, and really impressive.

A mega-battery is all very well unless it takes all day to charge. Happily, the C300e does not. It can rapid-charge, so its battery can be mostly recharged in the time it takes you to pop for a wee and ‘enjoy’ a sandwich at the motorway services. The BMW needs over two hours to go from zero to 80% charged.

The C300e is a pudding, though. Just like the old C-Class, it’s got artificially fast, lightweight steering that’s supposed to trick easily fooled badge fetishists into thinking it’s agile and quick-witted. Don’t be duped. Aim it at bends the BMW attacks with composure and the C-Class collapses into understeer. Even a hybrid BMW still feels planted, a bit more rear-wheel drive (despite having, as tested, xDrive 4x4 underneath), and reasonably well-balanced despite all the hybrid gubbins, though the upgraded M Sport brakes are horribly soggy and inconsistent. Just like the Merc’s. 

The C-Class is rapid in a straight line (and responsive enough for motorway surges on e-power alone) but it’s numb, wooden and by no means a sports saloon. It’ll be fascinating to see how AMG works this up into a new petro-electric C63, won’t it?

Especially given how comfy this new C is. My word, pillowy-soft pliant Mercs are back. There’s no clever road-scanning, adaptive shock trickery here. Just sensible spring rates (with air suspension at the rear to catch the hefty battery) and acceptance from the Germans that the rest of the world isn’t blessed with roads as smooth as their own. This is a luxuriously absorbent car. It’s lovely to do distance in. Unless you’re wedged in the back. 

In the front, Mercedes has made some unforced errors that chip away at yet more of the hard-won decades-old German rep for common sense cabins. It’s gone all hyper-minimalism like the S-Class, and sharp as the reclined iPad is, it’s not an unqualified success. Down the bottom, temperature and home buttons are constantly rendered. Those pixels never do anything else. So why not use tactile, high-quality buttons, and suffer fewer fingerprints? Why depend on “Hey Mercedes” when she’s as laggy as the screen if you dive deep into sub-menus?

The touch-sensitive sliders and swipeables on the steering wheel are absolute cack, and make operating luxury features like cruise control or the excellent hi-fi a pain – wearing away the sense of calm and relaxation the C-Class’s engineers have worked so hard to foster. 

Life in the BMW is more business-like. iDrive works in harmony with a touchscreen so you can pick and choose how you prefer to operate your infotainment. As usual, BMW’s digital dials are a complete mess, but at least there are proper buttons on the steering wheel, for adjusting the mirrors, and to tweak the car’s hybrid power delivery. Want to save battery charge or run in all-electric? Easy. Keep your eyes safely on the road and single-tap a button. In the Mercedes? Head down, delve into the touchscreen and hope all the traffic lights stay green, I guess. 

So, I’d rather travel in the BMW. I’d rather use the BMW’s dashboard. I’d sooner chuck the BMW down a twisty road. I also prefer how the BMW looks. There’s a few styling lines that go nowhere in particular, but compared to most of the brown bottomwater BMW’s design creche is spewing out these days, this is a handsome car. Incredibly, the C-Class manages to pull off being bulbously dumpy and simultaneously anonymous. And not as nicely proportioned as the old one. The aero-face wheels are interesting, at least. 

The BMW is the sharper, better sorted, more complete, less annoying car. But the C-Class’s magnificent powertrain is too efficient, too flexible and too crushingly clever to ignore. I’ve no doubt BMW will stuff a revised 330e with more batteries soon, but for now, the C300e might well be the world’s best PHEV. 

And that’s the takeaway here, from this grey day. Thanks for sticking with it, for the moment the plug-in hybrid truly came of age. The BMW 3 Series is still a superior car to a Mercedes C-Class, but the C300e is a better plug-in hybrid than the 330e – and just about anything.