New BMW 3 Series prototype review

We’ll see an all-new BMW 3 Series unveiled at the Paris Motor Show in October, but ahead of the car’s official launch in the autumn, Auto Express has already had a drive of a prototype next-generation 3 Series saloon.

To give you some insight into just how popular and important a model this is for BMW, the outgoing version (codenamed F30) enjoyed sales of more than 190,000 examples in its final full year in dealers, despite being due for replacement.

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In fact, it’s the German firm’s best-selling product, and the UK accounts for a great chunk of that popularity (24,000 of those 190,000 cars in 2017). So its replacement has a lot to live up to, not least on what has traditionally been the 3 Series’ key selling point: how it drives.

On initial impressions the new 2018 3 Series doesn’t do anything to change that. In fact, BMW’s head of application driving dynamics, Jos van As, told us that he and his team wanted it to feel “like a typically old-school BMW” when it comes to perceptions from behind the wheel, and that this was key in outlining the goals for the new project.

Those targets have resulted in up to a 55kg weight saving over the outgoing car, thanks to the CLAR cluster architecture platform on which it’s based (this will also underpin a new Touring estate, 4 Series Coupé and M performance models), with BMW’s typical balance still preserved by 50:50 weight distribution.

The track is also 30mm wider than before, while that weight saving has helped lower the centre of gravity by 10mm. Go for the sports suspension and there’s also a 10mm reduction in ride height. These elements all contribute to a claimed improvement in agility – and the new car definitely delivers it.

There are a few more technological features as well. The new 3’s suspension dampers are sophisticated. Our test car was built to what van As called “the engineer’s spec”. That means passive dampers instead of adaptive versions and the equivalent of M Sport trim with the M Sport Plus pack; so it features 19-inch alloy wheels, variable Sport steering and four-piston front brakes.

The dampers feature hydraulic bump stops and clever stroke-dependent technology. This means when the car is empty and therefore at its lightest, the damping rate is softer. This is possible because it sits higher from the road and there is therefore more suspension travel available, so the damping doesn’t have to be quite as taut.

When it’s loaded up with luggage or people, the damping is firmer because there’s less ride height and therefore less suspension stroke is available.

“It’s the right way to get the comfort when the car is empty and control over challenging roads or when it’s full,” said van As. Adaptive dampers will still be available as an option, though.

For the first time on a non-M Division model you can now get an electronically controlled limited-slip differential. The hardware is the same as in the current M3 and M4, only with reprogrammed software to suit the new application here. And that’s where van As and his engineers have really pulled off a trick.

The integration of all this new tech is the real key and what gives this new 3 Series the potential to top its class.

On first impressions it seems to have what it takes, because BMW has nailed one key area where a 3 Series saloon should deliver: dynamics.

The Nürburgring is an industry-favourite testing ground and with two laps of the tough German track to try out the car, following van As in an M2, the control from the new 3’s clever dampers is notable. The car turns sweetly, is sharp to change direction and roll is well controlled. So is the body, and over some challenging surfaces on broken roads, as well as the track, the dampers strike a sweet balance between compliance and support. Importantly, the front and rear axle set-ups are also well matched and give a nice sense of symmetry, instilling confidence when you up the pace.

It’s on the firmer side, especially on our car’s 19-inch wheels, but the clever stroke-dependent technology definitely works. On the road, even over harsher surfaces and nasty cambers that could confuse some rivals’ suspension set-ups, the 3 Series filtered out harshness without removing its trademark connection to the road surface.

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It’s not too severe a compromise to achieve the trademark response, because the damper tech means it rarely gets towards the end of its stroke – and when it does, those hydraulic bump stops reinforce the car’s plush, controlled feel. It’s fair to say it rides like a luxury car, but handles like a sports saloon should.

There are one or two drawbacks, though. While the chassis set-up is good, the steering doesn’t have that much life to it. The weight is nice in Comfort mode, but in Sport it feels a bit artificial, while the shortage of feedback is something common to pretty much all electric power steering systems. It’s an issue van As knows about and an area he and his team are working to improve before the new 3 Series is signed off.

There are no complaints about the car’s nimbleness, however. Better understanding of the alloy and steel CLAR platform has resulted in extra stiffness around the suspension top mounts, without having to add any weight into the car’s structure, which combines with redesigned suspension geometry to improve the direct feeling you get from the chassis.

The differential helps to boost agility on the way into corners and through direction changes as well, while the electronic control software means traction out of bends is also good.

Our 330i test car had plenty of power to exploit the benefits of the differential, too. Compared with its predecessor, there’s an extra 7bhp but an impressive 50Nm more torque from the 2.0-litre four-cylinder petrol turbo, so 256bhp and 400Nm in total. Thanks in part to the weight reduction, claimed fuel consumption is also improved by five per cent, although efficiency figures have yet to be confirmed.

The eight-speed auto works as well as it does in the larger 5 Series, and the 3 takes plenty of inspiration from its big brother, not least inside.

Although our camouflaged prototype didn’t have production-standard materials, we got a good idea of the cabin layout. It’s very similar to the 5 Series, with a large touchscreen placed in a great position on top of the dashboard, similar controls and features on the transmission tunnel (including iDrive) and a new digital dash panel that offers more configurability and information.

There’ll also be autonomous tech that subtly evolves what’s on offer in the 5 Series, we’re told, while the 3 inherits some of its sibling’s executive qualities as our autobahn tests showed. The car’s high-speed refinement is a clear step on from the outgoing 3 Series, while it’s resolutely stable, too.

There’s more space in the rear than before and it definitely feels roomier. While final dimensions haven’t been confirmed, a look in the boot indicated that it’ll be sized competitively, too.

source: AutoExpress Car Reviews (autoexpress.co.uk)

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