BMW X4 M review

The first of several large problems with how the X4 M drives concerns its ride comfort. Or the complete lack of it. Like its key rival, the GLC 63 AMG Coupe, the X4 M’s thudding, shatteringly stiff ride is totally unnecessary and ruins the car. With the AMG, things are a tad better in the SUV, but with BMW, you get the same intolerably firm ride with both the X3 and X4 versions, so there’s no escaping it. And at a stroke, the X4 M goes from being an odd car to a downright pointless one. 

Oh, it’s impressive on track, if you like irrelevances. We lapped it around the fearsome Monticello Motorsport Park in New York and the X4 M was easy to drive very, very fast. The brakes stood up terrifically well to repeated big stops from over 130mph, slowing the two-tonne X4 M reassuringly time after time – meaning BMW M is finally getting its act together with steel brakes as well as ceramics. That’s the good news. 

The bad news is that even with its rear-biased AWD and the stiff suspension and the ‘M Dynamic Mode’ stability control, the X4 M is a mute device. It doesn’t squirm under you or suggest rear-drive pretentions like an Alfa Stelvio Quadrifoglio or the AMG. It’s a point-to-point device. It’s very Audi-ish. One-dimensional. And back on the road, the ride’s too hard to enjoy any of it. And maddeningly, that’s true in Comfort mode, as well as the harsher settings.

Right, the engine. Here’s a stat for you: BMW has been working on the X3 M for four and a half years. The engine has taken closer to five years. It shares almost nothing with the 3.0-litre straight six you’ll find in the X3 M40i, other BMW M40is like the Z4, and the new Toyota Supra. It’s lighter than the old M straight-six, there’s less turbo lag, a 3D-printed head, and it develops 503bhp in Competition form. The old M4 GTS was a few horses down on that, and it needed a fancy water-injection system to get there. This engine’s got lots more headroom.

It drives the X3 M via the M5’s eight-speed automatic gearbox, which is fabulously smooth in manual mode but has a curiously haphazard shift strategy as an auto. And the M-specific gear lever is an ergonomic disaster. 

Of course, it’s a fast car, but so’s everything these days. Crucially, this isn’t an exciting engine. Not as bombastic as the Jag F-Pace SVR or GLC’s enormously exciting V8, nor as sharp and savage as the Alfa’s V6. Throttle response is fine, but BMW is still struggling to make a modern turbo engine sound half-decent.

Exhaust parp is synthetic and the hi-fi supplements engine noise, in an attempt to fool an X4 M passenger into thinking they’re in something palpably more special than an X4 M40i. BMW’s very proud of the 7,200rpm redline, but max power and torque arrive earlier, so the engine’s done its best work by about 6k. The rest of the revs don't do much.