BMW gives us the M Performance version of its seventh-generation 3 Series and also the first model with a straight-six petrol engine in the range, as the M340i lands. With a 374hp/500Nm 3.0-litre turbocharged unit under the bonnet, this thing's seriously quick. But is it seriously good, too?
In the metal
The BMW M340i is reasonably subtle to behold, especially if it's parked next to an M Sport 320i. It gains 18-inch wheels with mixed-size tyres across the axles as standard (19s are an option), as well as Cerium Grey exterior detailing for the kidney grille surround, the vertical intakes in the lower airdam, the door mirrors and the finishers for the trapezoidal exhaust pipes. The grilles in the nose have a mesh-effect finish, rather than vertical vanes, while subtle 'M' badging here and there completes the deal - but this is not a performance car that shouts about its credentials.
Inside, it's pretty much as you'd find any other high-spec 3 Series, so let's talk about the mechanicals before we get onto the driving. The 3.0-litre turbocharged straight-six from the Z4 M40i is appropriated and then fettled, and while its torque stays the same at 500Nm, power is hiked by 34hp to the 374hp peak. Now, in a 3 Series, that sounds like an awful lot - and, thanks to an eight-speed Steptronic Sport gearbox and xDrive all-wheel drive, it's enough to see the 1,745kg M340i hit 100km/h from a standstill in a searing 4.4 seconds. But it's actually down on power compared to three of its key rivals, with only the recently-turned-diesel 347hp Audi S4 TDI beneath it (mind, that car hits back with a ginormous 700Nm of torque by way of compensation).
With wider front and rear tracks than the old Mk6 340i, and a lower centre-of-gravity too, the M340i already has a decent dynamic basis, to which is added M Sport suspension, M Sport variable steering, M Sport brakes and an M Sport differential. There's also an M Sport exhaust system to make it all sound purposeful, so the M340i clearly has the hardware to provide an exciting drive. But does this on-paper promise translate into reality?
Driving it
There's no doubt this is a highly talented machine. Wet or dry, the M340i is going to be blisteringly quick, because it has a mega drivetrain and a magnificent gearbox, it has the ferocious responses of xDrive traction (you can get on the power so quickly out of a corner and the car will simply fire away at great pace onto the next straight with no drama whatsoever), and there's a wealth of mechanical grip in the set-up. All hooked up together, the BMW's superb body control adds to the mix and you can cover ground at a terrific pace with little effort.
And there's the problem: little effort. It's quite an easy car to jump into and drive very fast, very soon after you've set off in it for the very first time. And that's not something you could always say of rapid BMWs of yore. Now, we're not saying that BMW should be building actively dangerous cars just to satisfy a minuscule minority of raving-loony driving enthusiasts who want their motors to be hard work, but by the same token the thing that always used to mark BMWs out ahead of their Audi and Mercedes nemeses was their handling prowess. This 'very fast, very secure' approach is all well and good, but Audi's been doing that for years with quattro. Mercedes is also pretty handy at it these days, with its 4Matic system.
Also, in isolation, the steering and the sound of the M340i are two areas where we were left underwhelmed. The former pulls that annoying modern-BMW trick of being heavy yet largely feel-free in Sport mode, so that you spend your time trying to get the engine and gearbox into their sharpest character while dialling back the steering (the Individual mode is your friend here), while the latter is too artificial and buzzy on the ears - this is a big-hearted straight-six petrol, but the noise of it as it swings around to a soft rev-limiter at 7,000rpm is not what we'd call 100 per cent pleasant.
And while the ride comfort, the refinement and the general solidity of everything the M340i does are all admirable, you'll never shake that kerb weight from your mind. Heavy yet fast cars can mask their mass incredibly well with a myriad of suspension and bracing tricks, so that you think they're defying physics when you're accelerating and throwing them into corners, but one area where bulk can never truly be disguised is in braking - and the M340i takes a fair bit of stopping when it's on a roll. It's also hard to modulate its brakes smoothly at low speeds, as they can be grabby in city driving.
What you get for your money
As a range-topping model, the M340i does come with a lengthy list of standard-fit equipment. But it also has a starting price of €73,706 and its CO2 emissions will make it a pricey car to run here in Ireland, where we expect it will sell in tiny numbers.
Summary
Even accepting that the BMW M340i has to leave headroom in the range for an M3 coming down the line, we were perhaps expecting a bit more fizz and excitement from this 374hp saloon - but inert steering, a pervasive sensation of weightiness and synthesised noise from the engine are all areas that are something of a let-down. Nevertheless, the M340i is a deeply assured, mighty fast and easily exploitable performance car that is sure to delight the people who take a punt on it. It would make even more sense as a Touring estate, where it would be one seriously special all-year-round family machine - and about as close to an M3 wagon as we're ever going to get from BMW.
