New Audi A4 35TDI vs Mercedes C250d vs BMW 320d comparison

The petrol A4 didn’t quite cut it in the engine department, but the diesel version holds a lot more promise. We put it to the test against its German rivals

Published on Apr 14, 2017 07:00:00 AM

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New Audi A4 35TDI vs Mercedes C250d vs BMW 320d comparison

GRUNT OF THE LITTER

This 2.0-litre ‘35 TDI’ diesel engine was something we’ve been anticipating since the A4’s launch last year, but unfortunately Audi had to spend the time retrograding this Euro-IV engine to work with our poor-quality BS-IV diesel. Amazingly, they’ve done it without any loss in power or torque, and the global figures of 190hp and 400Nm remain intact. The other thing that’s stayed unchanged is that refined nature of the VW Group’s latest EA288 diesel engine. Sure, there’s a grumble at startup and a gruffness if you open it up all the way, but at idle and regular cruising speeds, it’s freakishly silent.

Despite an improvement with the new engine, the BMW is still quite noisy, but it never feels too gruff. That’s probably because it is quite a pleasing growl, one that you’ll want to hear as you rev the daylights out of it; all part of that sporty appeal. But it is a mark down on the luxury quotient nonetheless.

The C-class’ noise is a bit more clattery, and it’s the one that lingers in your head long after you’ve stopped driving. Apart from the noise though, this is an incredibly smooth powertrain. The 204hp, 2.1-litre motor just whooshes its way across its rev band, pinning you back with one constant surge of 500Nm across the rev range. No step in power, no sudden punch in the guts and very little turbo lag, and that’s largely down to the superb new nine-speed automatic, which just shifts its way around the sluggish zones. You’d think, with so many ratios, you could catch it off guard, but that’s very rare. It’s so smooth and seamless that you can barely tell it’s shifting.

The BMW uses the ‘old faithful’ ZF eight-speed auto, and while it’s still one of the best in the business, it seems this iteration can’t quite match Merc’s 9G-Tronic for outright smoothness. Still, that does, again, suit the 320d’s sporty character better. It’s still very clever and intuitive, it’s just that you’re more aware of the shifts, and there is that characteristic spiky punch when you kick down for an overtake. The Bimmer’s motor just loves to rev out, almost like a petrol engine, especially in Sport+ mode, encouraging you to pin your foot down at every opportunity. The best part is it doesn’t sacrifice drivability, and in Comfort or Eco Pro modes, it’s as docile and manageable as you expect in a luxury sedan. And while on the topic of the modes, the BMW doesn’t get a customisable Individual mode like the others, but then each of its available modes feels distinctly different; in the other two, the differences aren’t as stark.

Mercifully, Audi has finally let go of its Multitronic CVT gearbox for this generation of A4, moving to its superb S-tronic seven-speed double-clutch auto instead. The new motor is typical of the VW Group in more ways than refinement, though, and it’s the one that displays some lag when you want to get going in a hurry. When you don’t, however, it’s smooth and unobtrusive, and you’ll never notice it working away. Like the BMW, it too gives you a solid ‘whump’ in the chest when you kick down hard, as it hikes up its skirts and surges ahead.

All three are in the same ballpark getting to 100kph from rest, the Audi doing it in 8.08sec, the Mercedes in 7.89sec and the BMW, clearly the quickest, in 7.25sec. However, these 320d times were tested on the M-Sport version with launch control, so we wouldn’t be surprised if this standard car ends up being closer to the Merc’s time. It also explains why both the others are over half a second ahead at 150kph. Interestingly, it’s the Audi that’s the quickest in kickdown acceleration by around 1sec, when compared to the other two, so don’t be quick to label it a slouch.

A MATTER OF RIDE

This particular segment of luxury sedans calls for a balance of comfort and dynamics that’s not as important in the higher segments, where outright luxury is more important. So, of course, the 320d comes to mind right away. BMW’s witchcraft is at play once again, somehow letting the 3-series handle like a sports car half a size smaller. The way it clings to the road, keeps roll and body movements under tight wraps, and how the steering – though a touch on the heavy side – just feeds you with all the information you need from the nose. This one is still the driver’s choice, make no mistake of that. And yet, the ride doesn’t suffer for it. At slow to medium speeds, it’s really comfortable and doesn’t get unsettled easily. It’s only really sharp bumps that will make a noisy entry into the cabin when you hit them, but that’s still at a forgivable level.