There is something undoubtedly alluring about a powerful rear-drive coupé such as the M240i. This is a part of the market where affordability makes compromise common – where hatchback-based front-drive pseudo-coupés jostle with true three-box designs.

With the 2 Series, however, BMW has seized the opportunity to offer both a purer vision of a downsized two-door and a proper BMW to boot, with a longways engine, driven rear wheels and the unmistakable separation of roof and bootline that makes a coupé a coupé. It’s a commitment that has produced a distinctive, desirable car. Using this fine blueprint BMW also whipped the roof off and replaced it with fabric in the shape of the convertible - and to their credit have also included the M240i into that range too.

Matt Saunders Autocar

Matt Saunders

Road test editor
BMW's M Sport brakes are standard, with four-piston calipers up front

Because it’s a 2 Series, of course, a bit of growth relative to the 1 Series coupé was inevitable. So the M240i is 110mm longer than an M140i three-door, as well as 72mm longer than the old 135i coupé.

The car’s styling is distinguished from that of the 1 Series hatchback, with which it shares some panels, by different headlights and bumpers. You can spot an M240i over a lesser 2 Series, meanwhile, by its large front air dams, the absence of front foglights, the grey door mirrors and the smoked exhaust pipes. For the 2017 facelift, BMW gave the M240i a new set of LED lights at the front and rear as standard, alongside tweaks to the air intake and famous BMW kidney grille. Inside the ergonomics have been altered to be more driver-focused, plus touches of chrome, new air vents and the latest iteration of BMW's iDrive infotainment system - including a touchscreen display.

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The M240i rides 10mm lower than a standard 2 Series and gets passive M Sport suspension, enlarged M Sport brakes and special Michelin tyres. Adaptive M Sport suspension, with variable dampers, is optional, and came fitted to our test car.

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.

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