BMW 3 Series saloon - Engines, drive & performance
Agile, comfortable and quick, only its lifeless steering spoils the 3 Series as a driver's car
The latest BMW 3 Series sticks to the time-honoured layout of front engine and rear-wheel drive, which has underpinned the model since the early 1970s. However, progress has brought subtle changes over the years, and each incremental change has mounted up to make today's car thoroughly state-of-the-art.
As ever, the 3 Series is available with BMW’s xDrive four-wheel-drive transmission – for drivers who want more traction in slippery conditions.
A clever suspension design is also among the list of improvements made to the 3 Series for the seventh generation. Described as ‘stroke dependent’, it provides softer damping when the car is lightly loaded, becoming firmer as the car's weight increases. It’s certainly an effective set-up, and even on poorly maintained UK roads the suspension certainly maintains a supple ride without upsetting the BMW's composure in corners.
Better still, this new found comfort isn’t at the expense of the BMW’s sporting nature. The Sport trim offers a great compromise between ride and handling, while M Sport cars are firmer for added cornering prowess, without crashing into most bumps.
Although the ride is firm on the worst British roads, the 3 Series is far from uncomfortable. Bumps are rounded off nicely, leaving passengers exposed only to mild jolts, rather than the severe shocks that once plagued sporty saloons. Road surface imperfections tend to be betrayed in a little more detail, though, when the larger 18-inch alloy wheels are fitted – you get a sense of bumps and ripples in the road surface more easily. Buyers wanting greater comfort should consider the optional adaptive dampers, which can be adjusted to soften or stiffen the ride to taste.
The upshot of the bigger wheels and wider tyres is an even more grippy, responsive car. With the rear wheels further apart than the front (a measurement known as a car's 'track'), the 3 Series feels very assured and stable, which leads to a real sense of confidence when you head into a corner. The only thing that detracts from the BMW as a genuinely rewarding car is the steering, which has the slightly remote, uninvolving feel from which fuel-efficient electric power steering systems often suffer. It’s also quick to respond, which feels great on a twisty B-road, but can make the M Sport version feel slightly twitchy on the motorway.
Honed by BMW's M division, the BMW M340i xDrive is the hottest version of the 3 Series in the regular range, sitting beneath the BMW M3. In this niche of mid-level performance saloons it goes head-to-head with the Mercedes-AMG C 43 and the diesel-powered Audi S4, offering enthusiasts a great chassis and rapid acceleration. It arguably doesn't feel quite as special as its Mercedes rival, but there's no denying its ability to cover ground at an astonishing pace. It has excellent body control and direct steering, and while it’s certainly agile, adaptive suspension means it can also be as comfortable as regular versions.
BMW 3 Series diesel engines
The 320d badge is a familiar one because it’s on the rear of so many 3 Series models sold. The rear-wheel-drive model also gets the same mild-hybrid assistance used in the now-discontinued 318d. This consists of a 48-volt starter generator and a small battery that’s charged using the energy normally lost under coasting and braking, providing a boost of up to 11bhp. With a 187bhp power output and low running costs, it seems likely to remain a popular choice among buyers of the latest generation 3 Series.
In true diesel style, its performance is better described as effortless than exhilarating, but 0-62mph in 6.8 seconds is pretty quick, and a 149mph top speed ensures relaxed high-speed cruising. Thanks to its advanced turbocharging, it very rarely feels out of breath either. It proves quiet when a constant speed is maintained, and – while it gets a little loud at full throttle – it's less noisy generally than the previous model.
The eight-speed automatic gearbox changes through the gears almost imperceptibly, and manual gear changes are just as prompt and smooth when you take manual control via the steering wheel paddles. However, the gearbox is so well calibrated that you might as well just leave it in full automatic mode and save yourself the effort.
The M340d xDrive takes just 4.6 seconds to hit 62mph, making it one of the fastest diesel cars on sale. If you need a fast executive car to cross continents in, there’s a lot to be said for a straight-six diesel that can make motorway speeds appear effortless.
The petrol 318i was previously the cheapest 3 Series available, but it was discontinued for the 2022 facelift as BMW slimmed down the lineup. With 154bhp, it also had the lowest power output of the range but was still pretty capable, with 0-62mph taking only 8.4 seconds.
The rear-wheel-drive 320i now forms the entry point, with 181bhp and 0-62mph completed in a reasonably swift 7.4 seconds. It’s also good to drive, with poised and well-balanced handling that’s reminiscent of the BMWs of yesteryear, with a slick eight-speed automatic gearbox making it a strong all-rounder.
We expect the 320i will be plenty for many petrol fans, although there are a couple of faster-still versions. It’s worth noting that every 3 Series now comes with an automatic gearbox as standard.
The 330i petrol, which is the second petrol choice currently available, is a 2.0-litre, four-cylinder engine and not the 3.0-litre six-cylinder engine you might expect if you’re familiar with the way BMW has historically badged its cars.
That fact might disappoint some BMW fans, but they need not fear any shortage of power. In fact, the 330i produces 254bhp, which is a figure once reserved for much bigger, thirstier engines. BMW claims it's enough for 0-62mph in just 5.9 seconds, allied to a 155mph top speed. And, while it can't match the silky feel of a six-cylinder engine, it makes a pleasant noise and revs enthusiastically towards its 5,000rpm power peak.
The new BMW M3 is the height of 3 Series performance, with 503bhp and a sub-four second 0-62mph time making it one of the fastest saloons you can buy. It does have divisive looks and an eye-watering £75,000 price, so many buyers will be drawn to the M340i xDrive instead. It’s almost as quick but close to £25,000 less expensive. We found its 369bhp, 3.0-litre turbocharged engine to have more than enough power to satisfy all but the most demanding of enthusiasts – 0-62mph takes just 4.4 seconds, thanks in part to the standard M Performance four-wheel-drive system. That’s quicker than the last generation of BMW M4.
In essence, the example we tested felt like a shrunken BMW M5 super saloon. The four-wheel-drive system is unobtrusive, so the M340i xDrive feels more like a very obedient rear-wheel-drive car most of the time. It makes the right noises, though, with characteristic pops and bangs from the exhaust when you lift off the accelerator. Change into Eco mode and it also settles down and becomes civilised enough to shrug off a congested commute with ease.
One of the most intriguing versions in the range, the BMW 330e has both a 2.0-litre petrol engine and a powerful electric motor. Combined, these provide up to 288bhp and get the 3 Series from 0-62mph in six seconds. That's not quite the end of the story, though, because when Sport mode is selected, there's something BMW calls ‘XtraBoost’, summoning a further 41bhp from the electric motor - provided there's enough charge in the battery pack.
It feels quick, even if the petrol engine can sound a little strained under hard acceleration. The rest of the time the 330e is just as good to drive as other versions, and of course, at low speeds it's incredibly quiet. You'd be hard pushed to notice the extra heft of the 330e either, because its engineers seem to have disguised the weight of its batteries and extra tech remarkably well. It has sharp steering and excellent handling.