If you want a high-performance 3 Series but you don’t want to shout about it, then the BMW M340i is definitely for you…
It’s hard to believe we’re now in a world where a 374hp BMW 3 Series that can do 0-62mph in 4.4 -seconds is not classified as a full M car. But that’s where we are right now – and this is the first time since BMW’s modern turbocharged-petrol era began with the E92 335i that the company has felt confident enough to bestow the ‘M Performance’ tag on its forced-induction six-pot Three. M Performance is one step down from full M; doesn’t feel like it, though, when you look at the stats of this G20 3 Series flagship. The M340i uses a derivation of the B58 engine as used in the other ‘M40i’-badged cars – so think the BMW X3 and X4 M40i, or the Z4 M40i – only here, it’s ten percent more powerful. That means 374hp, instead of 340hp, although it has the same peak 369lb ft to back it up. Power flows to all four corners through an eight-speed Steptronic Sport automatic and xDrive transmission, which allows the M340i to turn in that blistering 0-62mph sprint… despite the fact it weighs 1,745kg. That’s just 50 kilos lighter than the E39 M5, by the way, and 26hp less. And the two cars have the same torque.
Like the kind of underplayed way BMW talks about this M Performance 3 Series, the car’s looks are quite sedate. It’s available as either a four-door saloon or as the handsome Touring, and the UK is a key market for this model – one of just two six-cylinder 3 Series left, along with the 330d. We’re expected to be the second biggest global market for the M340i saloon, after the US, with our appetite for the Touring version only beaten by customers in Germany (which, incidentally, ranks seventh in the world for the saloon model) and Switzerland.
But neither saloon nor Touring M340i is particularly showy. Cerium Grey details are the key signifier that this is the 374hp model, so look at the kidney grille surround, front vertical air intake bars, door mirrors and the trapezoidal tailpipe finishers for those. As standard, the M340i sits on 18-inch wheels with staggered tyres front-to-rear (225/45 and 255/40 respectively), with the option to enlarge them to 19s wrapped in 225/40 front and 255/35 rear rubber. Inside, it’s virtually indistinguishable from an M Sport Three (save for a smattering of ‘M340i’ identifiers), although it is a very high-quality place to be.
The M340i compares favourably with the F30 340i range-topper in a number of chassis areas, such as its front track is 43mm wider, its rear track is 21mm broader, the centre-of gravity is closer to the deck by 10mm and the car is up to 55kg lighter. M Sport suspension, variable M Sport steering, M Sport brakes and an M Sport differential are all part of the standard package, while options include Adaptive M suspension with variable dampers. To drive, the M340i is immediately impressive and composed, but not what we’d call thrilling. The drivetrain is mighty, of course; that 3.0-litre turbo six is supremely strong and it punches hard from very low revs, aided and abetted by the super-fast eight-speed auto and the xDrive. So there’s no problem with
the sheer speed of the M340i, but we do have reservations about the noise. It has an M Sport exhaust system as standard, yet it’s not so much the muted rumbles and thuds of the pipes that bother us; rather, it’s the cloying, thick, buzzy noise of the engine, which sounds like its exertions have been over-synthesised. The steering is also too heavy in Sport mode. This is a trait we’ve noticed in a few hot products from BMW recently, although it doesn’t seem to apply to all – the X2 M35i, for instance, isn’t similarly afflicted. There’s not much in the way of feel in the M340i’s set-up, so it’s a relief that the steering is at least accurate and consistent.
However, because the G20 is a fine handling car in lower specification than this, there’s much to praise with the M340i. There’s little in the way of understeer at reasonable speeds, and you can certainly feel that the xDrive system is rear-biased, especially if you commit to a corner with a crest midway through it – then, you’ll feel how lively the rear axle is, so BMW’s traditional handling traits are being preserved. The brakes are good and strong and communicative, and control of the body is excellent on the M Sport suspension. It all adds up to a car that is tremendously quick across the ground in the dry, and one which will probably be sure-footed and rapid even when it’s raining, thanks to the traction advantages of its all-wheel drive.
It’s just that… you’re always aware of its weight while driving it. To cruise along in, the M340i is lovely, smooth and supremely refined, with a great ride and minimal wind noise, so it feels like a big luxurious limo. And it feels a bit like a big (if very well-sorted) luxurious limo in the corners, too; something that is deeply assured, but perhaps not something you’d want to go to the very limits of grip and weight transfer in. This is not something we’ve thought of previous fast Threes.
But therein lies the rub. A new M3 (and associated M4) is on the way in a couple of years and it is – like its M5 big brother – surely also going to have to go xDrive (for the most part…) to corral something like 500hp. So those looking for ultimate driving thrills will be catered for by that. The M340i, meanwhile, is the all-rounder, the one you can use throughout the year and enjoy its prodigious pace without having to work too hard at it. Maybe the only thing that makes us slightly uneasy about that summation is: you could just as easily apply that statement to an Audi Quattro or Mercedes 4Matic…
Watch this video for First Drive BMW M340i xDrive High-Performance