BMW 3 Series saloon performance
Despite numerous stories spreading the dirt on diesels, expect the 320d to buck that rhetoric and remain the most prolific of all the 3 Series’ engines – for now, at least. It’s a 2.0-litre four-cylinder unit that pumps out 187bhp, and it’s just the ticket if you’re looking to balance economy with performance. You get plenty of poke from low to mid-range revs, so there’s no need to hoof it to gain speed, which makes it relaxing to drive. And when you do work it hard, it’s as pacy as the C220d and A4 40 TDI. If you desire a diesel with more shove, a six-cylinder 330d is on the horizon.
If petrol power is your cup of fossil fuel, you'll need to look to the 254bhp 2.0-litre engine of the 330i. Although this needs working harder than the 320d, it's ultimately faster and emits a sporty rasp when revved. If you value performance over economy, it's well worth considering. We've also tried (albeit very briefly and only on track) the range-topping M340i, with its mighty 369bhp 3.0-litre straight-six. Not only is it seriously rapid, but it's also muscular throughout its rev range and makes a delicious howl when pushed.
The 3 Series comes with either a six-speed manual or eight-speed automatic gearbox. We haven't tried the former yet, but the latter is extremely responsive – more so than the A4’s hesitant dual-clutch unit, so you’re never left hanging when overtaking.
BMW 3 Series saloon ride
The best version we’ve tried thus far is the Sport. Fitted with standard suspension, 18in alloy wheels and optional run-flat tyres, it sits just on the right side of the comfort line. It’s very well controlled, so over heavily undulating roads it won’t bounce you out of your seat like the C-Class can, yet it’s supple enough that bigger, soft-edged bumps, such as sleeping policemen, are ridden over with a good degree of grace.
It’s the smaller imperfections that catch it out, though. Small but regular ripples make it shimmy annoyingly, whether you’re in town or travelling at speed on the motorway, while sharp expansion joints and ridges cause a notable jolt. In these respects, the C-Class, even on its sportier AMG Line suspension, is more forgiving and relaxing, and the A4 is better still when equipped with the optional adaptive suspension.
There are different options for the 3 Series that might make it better, although these have been unavailable for testing to date. They include adaptive dampers, which are available specifically for M Sport trim (as part of a pricey option pack).
We have tried an M Sport on its default, stiffer passive M Sport suspension and optional 19in wheels; it's even better controlled, but impacts over sharp road imperfections are even more pronounced, so be warned. You can delete the M Sport suspension at no cost, though.
BMW 3 Series saloon handling
Over the past few years, BMW has come under fire for dropping the ball over its fabled sporty driving dynamics; remember all those adverts banging on about 50:50 weight distribution? Well good news: the latest 3 Series is BMW back to its brilliant best.
Its steering set-up represents perhaps the first time since electric power steering became the norm that BMW has managed to deliver something truly exceptional: the weighting is consistent and it communicates a good sense of the road surface beneath through the wheel rim.
This induces a far better sense of grip and tells you more instinctively how much steering angle to apply, which is a good thing, because the steering is quite quick off centre. It takes a bit of getting used to but undoubtedly makes the 3 Series even more reactive to inputs than the XE – let alone the A4 and C-Class.
Body control is first class, too. Where the C-Class leans more and takes time to settle between quick changes of direction, the flatter-cornering 3 Series will zip left and right like a mouse being shooed by a flighty broom. It’s also beautifully balanced, with reliable front-end grip that lets you carry speed into corners, coupled with plenty of rear grip that makes the car stable through the bend and out the other side.
BMW 3 Series saloon refinement
Wind noise is very well contained at motorway speeds, but road noise (on the selection of run-flat tyres we’ve tried so far) is slightly worse than in an A4. Suspension noise – again, probably not helped by the stiff sidewalls of the run-flats – is also pronounced over bumps.
The 320d's engine is pretty muted compared with a C220d's, but the A4 40 TDI is even quieter. The 3 Series’ optional eight-speed automatic gearbox, meanwhile, is smooth when changing up through its gears and far slicker than an A4’s dual-clutch S tronic ‘box at parking speeds. Just before coming to a halt, though, you can often feel it lurch into first gear, which exacerbates an issue with the brakes; the pedal has little resistance at the top of its travel so, on top of how the gearbox adds a sudden pulse of engine braking, it’s easy to unwittingly brake a little too hard and bring the car to a surprisingly abrupt halt.