What is it?
Despite not being a ‘proper’ M car, the M135i has become something of a cult classic among the automotive community. First released in 2012, it’s one of those machines that doesn’t look particularly exciting on paper but offers a truly special driving experience. It is, without doubt, one of our favourite hot hatches.
So why, you might ask, has BMW gone to the effort of replacing the M135i with the new M140i? After all, if it ain’t broke, don’t fix it. Well, it turns out that BMW is well aware of this idiom and has embraced it, choosing to update the current car rather than overhaul it. The badging has been altered to bring the M140i in line with its M240i and 440i coupé siblings and the sonorous 3.0-litre engine has been replaced with an even more powerful 335bhp six-cylinder motor - up 14bhp. No downsizing here, thank you very much.
Read more: Britain's best affordable driver's car - BMW M140i vs Honda Civic Type R
What's it like?
Unsurprisingly, with its six-cylinder turbocharged engine producing the same power and torque as the iconic 1M Coupé, the M140i is properly quick in a straight line. If you can get it hooked up (made all the more difficult thanks to the absence of a proper limited-slip differential), the hatch can complete the run from 0-62mph in just 4.6sec, a considerable 0.3sec quicker than the model it replaces.
However, despite this remarkable turn of speed, it’s the engine’s flexibility that’s most impressive in the real world. Unlike the Focus RS or Civic Type R, you can barely detect the signs of forced induction, with the six-cylinder motor responding almost instantaneously at any revs. We came to love this linearity in the M135i because it allowed the BMW to play two very different roles: long-legged GT cruiser and M car screamer. This characteristic has not only been retained but also accentuated in the M140i.
Our test car came fitted with BMW's ZF automatic gearbox, and although there’s no doubt that the manual gives an extra level of interaction, we simply can’t fault the eight-speed unit. It’s quick and responsive and the ratios are well spaced to make full use of the motor’s broad powerband. The gearbox is also now capable of making multiple downshifts in one go, giving even greater control.
Dynamically, the M140i feels almost identical to last year’s M135i, but that’s no bad thing. Compared with its firmer competition it feels unique, thanks to a chassis that makes the most of its rear-wheel-drive layout. The front axle is super-responsive and gives the BMW impressive turn-in speed. There is a little mid-corner lean, but once the body settles you can lean on the car’s innate traction to fire it out of bends.
There are limitations though. On really rough roads there's a point where the suspension finally cries enough and fails to react to multiple inputs. Mid-corner this can cause the car to feel unsettled and loose, and combined with the lack of a limited-slip diff and its overly light variable-ratio steering, a Mercedes A45 AMG or Volkswagen Golf R would leave the BMW for dust on a bumpy rural road.