Used BMW M240i Coupe 2016-2021 review

Delve into BMW’s M Performance dealer-fit accessories catalogue and you’ll find that an even more purposeful passively damped set-up is offered, as well as even more powerful brakes, lightweight forged 19-inch alloys and an M Performance mechanical limited-slip differential. Our test car had none of the above.

Power comes from BMW's twin-scroll turbocharged 3.0-litre straight six, in a more developed state of tune than we found it in the M135i, but when BMW renamed the range, they also turned up the wick, so the M240i now produces 335bhp and 369lb ft - with the peak twist figure intriguingly matching that produced by the M2.

BMW’s N55 3.0-litre turbocharged straight six has been through enough updates and revisions to cause a codename-related headache. In many lesser applications the engine is simply dubbed the N55 (to distinguish it from the earlier twin-turbocharged N54), and develops 302bhp and 295lb ft of torque.

In 2012 it found its way into the M135i with an improved 316bhp and 332lb ft and was rechristened the N55HP. The original M235i received a new ECU and cooling system, the unit produced 322bhp in the M235i. By 2016, BMW wanted to up the ante, the arrival of the M2 was heralded and the tweaks to the M240i went rather unnoticed, with the headline figures left to make a statement on their own.

On top of all that, the 3.0-litre straight six used in the new M3 and M4 is an even more substantially respecified N55. Codenamed S55, it has power and torque outputs that are both well into the 400s.

In all cases, the N55 uses one twin-scroll turbocharger, whereas the old N54 had two. Equally confusingly, Alpina’s current B3 saloon uses the N55 block, but the firm junks BMW’s single twin-scroll turbocharger and fits two separate blowers of its own design.

All of which leaves the M240i a little short on the outright poise it’d need to rank as a truly outstanding driver’s car. It’s not short on lively interactivity or boisterous rear-drive charm – just a final degree of finesse.

Aside from affecting outright performance, bad weather prevented us from revealing the BMW's full potential on MIRA’s handling track. Experience elsewhere suggests it might have been spectacular, but not as spectacular, we’d wager, as it would have been had our test car come with the optional mechanical LSD and trick suspension.

In the wet — and on worn tyres — the car had much more performance than it could put down and handled as if up on tip-toes. The same initial balance and bite we found on the road was present to begin with, but the progressiveness and controllability of the car quickly ebbed away at the limit of grip with the stability control disabled.

Above a certain point, the BMW ran seriously short of grip and started to understeer markedly. Better that, however, than run out of stability at the rear end first.

It’s a shame, but we can conclude that M240i owners would be well advised to keep their tyres fresh if all-season usage is what they intend.