BMW M340i, BMW 3 Series M340i xDrive, BMW M340i xDrive, BMW

This is the most powerful version yet of BMW’s latest 3 Series. With all of its seventh-generation siblings running four-cylinder powerplants, the M340i is also the only new petrol 3 Series to have a six-cylinder engine. The luxuriously equipped M340i xDrive has been conceived and developed in close co-operation with BMW’s M division, hence the M in its name. It fills the gap in the German car maker’s line-up between the excellent 330i and the upcoming new M3, due in 2020.

The M340i xDrive is the only remaining six cylinder petrol 3 Series, because there’s no M3 yet. It can be had only with four-wheel drive. It sits hard up against the Audi S4 Quattro and C43 AMG. It’s not just a normal xDrive 3-er. The persons from M have had a go.

Climb into the M340i xDrive and you’re met by a classy-looking cabin, which on first acquaintance feels more luxurious and of higher quality than any direct rival’s.

The front seats provide a good deal of support, the leather-bound multi-function steering wheel is nicely proportioned and the dashboard reflects BMW’s efforts to give its most powerful 3 Series model a truly upmarket air, with digital instruments, expensive-looking chrome trims and a 10.3in touchscreen display for infotainment functions. It instantly feels special and suitably sporting.

One must-have option for every prospective M340i xDrive buyer is the head-up display, as featured on our test car. It operates over a much wider section than rival units, providing the driver with an impressive range of information, including selected driver assistance systems, cruise control and navigation directions – all in your natural line of sight.

The M340i xDrive’s engine revs freely and eagerly up to 6800rpm, making it more entertaining than the smaller unit used by the 330i. It’s also nicely tuned, with an exhaust note that goes from whisper quiet to raucous, depending on your mood.

BMW M340i, BMW 3 Series M340i xDrive, BMW M340i xDrive, BMW - The Interior
BMW M340i xDrive Interior

In what way?
It has their input in the cooling, exhaust, brakes, e-diff, steering rack, springs and dampers. Even a pair of the rear suspension links have been changed versus a normal 3 Series.

This uses the latest version of BMW’s (not M’s) 3.0-litre straight six, at 374bhp. It’s more fuel-efficient as well as nearly 40bhp more powerful than the old 340i. This is the engine that might have gone into the Z4 M40i/Toyota Supra but didn’t because it wasn’t ready. So that’s their facelift engine sorted then.

Enough numbers. Does it feel fast?
Brisk. Really brisk. It’s in that order of performance you can still enjoy properly using on the road, rather than the sort where you’re off the throttle as soon as you’re on it because you’re illegal too soon.

It departs from low revs with little lag. And with little of the sense of driveline inertia you get with many 4WD cars. Then it swings progressively all the way to 7,000rpm. Clearly enjoys it too, with that sweet harmony in the middle and sharper voice as you work it to the top. But it’s civilised. None of that fake exhaust fireworks, thanks.

There’s just one turbo, by the way, not the theoretically quicker-responding pair of small turbos (BMW’s ‘Twinpower’ label means twin-scroll, not twin-turbo). Why just one, I asked the engine chief. Cost, came the refreshingly honest reply. But it isn’t spoilt.

Am I right in guessing standard 4WD takes away the fun?
You are not. There’s a fine clarity to the steering, and a willingness to change direction. It feels lighter than it is, in a good way. The steering’s informative too, and the car is one of those rare ones where you feel the tyres working even when they’re well inside their limits.

Get more force into them and you’re told good and early when you’ve arrived at the bend too suddenly (mild understeer) or are negotiating and departing it under the approved amount of power (mild oversteer). The slip angles are there to be exploited but they’re road-appropriate. The ‘Sport’ mode sets the bias more rearward.

Brakes, four-pot jobs, do a fine job, and M even went to the trouble of moving the actuator’s pivot point to shorten the travel just for this car.

The ride, like other 3 Series versions, is on the firm side but not unbearable. Adaptive dampers are optional, and 19-inch wheels too. I had them on the test car, and the ‘Adaptive’ mode was best, rather than ‘Sport’ or ‘Comfort’. In other words, trust the engineers.

I sense you like it?
Oh I very much do. It just hits a sweet spot – looks moderately quick, sounds moderately quick, is actually a bit quicker again. But with a sensitivity to its actions that’s deeply satisfying. Not brutal like some of the bigger M cars, but drivable and really habitable.

Do they do a Touring?
Absolutely. What more could you want?

Should I buy one?
The M340i xDrive is arguably all the car you’re ever going to need, It’s versatile, high on quality and features and, thanks to the endearing nature of its engine as well as its M-tuned suspension, quite special to drive, too. If you could live with its sometimes knobbly ride, it should definitely be on your list.

BMW M340i xDrive specification
Where Munich, Germany Price £48,555 On sale Now Engine 6 cyls, 2998cc, turbocharged, petrol Power 369bhp at 5500-6500rpm Torque 369lb ft at 1850-5000rpm Gearbox 8-spd automatic Kerb weight 1670kg Top speed 155mph 0-62mph 4.4sec Fuel economy 40.4mpg (WLTP) CO2 160g/km Rivals Audi S4, Mercedes-AMG C43.