“Apparently, the auto should duck under five seconds to 60mph,” said one tester, prior to our trip to MIRA proving ground in the M135i. Yet this car has no launch control, our test car had completed some photography so was on part-worn tyres, and it wasn’t the world’s driest or warmest day when we arrived at the test strip.

So even though BMW is frequently conservative with its performance claims, we were surprised when, two up and with a full tank of fuel, the M135i posted a two-way average 0-60mph sprint of just 4.6sec.

Matt Prior

Road test editor
The engine's soundtrack is nicely busy most of the time, but eases off at a motorway cruise

That is ludicrously rapid for the money and a reminder to models such as the Vauxhall Astra VXR and Volkswagen Scirocco R that a car can have all the power it likes, but if it doesn’t send at least some of its drive to the rear, it can forget trying to match the BMW.

Not that the M135i is any less shabby in or through its gears, as a quick glance at the acceleration figures on p64 will show. Want to go from 30-70mph using only third gear? It’ll take just 4.1sec. Even in sixth – which is barely past idle at 30mph – the BMW wants only 8.1sec, which is amply brisk. For all its power, the M135i’s unit is exceedingly flexible, smooth and happy to be rolled out from low engine revolutions.

Do we think it’s a disappointment that it isn’t naturally aspirated, with the same whip-crack response as a true M engine? No more so than you’d think. Both the gently blown six and the smooth-shifting conventional automatic may seem at odds with the M badge, but given the car’s ‘halfway’ status, it’s as responsive and keen as we’d reasonably expect. There’s only a little turbo lag at low revs, and you have to search for it.

Meanwhile, if the eight-speed auto shows any hesitancy in Drive, it’s no bother to shift it to Sport and make the changes yourself. Certainly, the drivetrain is as compelling as any in a direct competitor’s vehicle and, truth be told, you can’t ask for much more than that.

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