BMW M4 convertible first drive

The new open-top BMW M4, a convertible whose manners have clearly been tamed for ambitiously rapid high-speed cruising. 

Like the M3 convertible before it, the BMW M4 convertible is a slightly troubling device for car lovers. This is a machine whose main reason to exist is the exhilaratingly tactile pleasure of driving it as rapidly as you dare. 

That’s why the M4 coupé has a 431bhp turbocharged straight six engine, fat tyres, a front bumper gaping with air-guzzling grilles, and the option of a swift-shifting seven-speed, paddle-triggered transmission.

The M4 convertible has all this too, but it weighs more and is inevitably less rigid to the potential detriment of the road manners that are a BMW Motorsport model’s priority. 

And this downside has applied to every one of the now five generations of roof-retractable M3 and M4s.

None of which has deterred the 60,000-odd global customers who have bought a drop-top M3 over the past 26 years. If you want the top-of-the-range high-performance 3 or 4 Series, this is your car, and plenty of sun-lovers will settle for nothing less.

A car that’s very similar to the M4 coupé in terms of style, performance and driving substance.

Fire up and the exhaust is all blare and promise, and you won’t be disappointed when you unleash the straight six - 406lb ft of torque floods in from 1850rpm to 5500rpm, at which point you ride peak power all the way to 7300rpm. 

This is a sensational engine, and its roof-off impact is all the greater for hearing the suck of induction and the blast of exhaust. The quad pipes sing harder in sport mode than in more eco-friendly settings too, and sometimes loudly enough that you’ll want to control their volume separately rather than via the engine throttle map. 

The M4’s dynamic performance survives largely intact, although its polish has dulled in places. The convertible’s steering feel can seem curiously fogged at times - though the sensation is rare -  and you can detect a faint, fast-pulsing shake through the body on choppier surfaces. 

In hard-charged bends, too, you’ll feel the 70kg deadweight of a roof flat-packed a few feet behind you. If you set out to look for these differences, you’ll find them. But they’re small, and unless you obsess about them they barely diminish the very considerable thrills of this car, which are quite often magnified to glorious effect by the removal of its roof. And that includes swooping through curves.

In the dry the M4 has the grip of wall-climbing gecko, but in the wet it’s not so hard to get the orange traction control light flickering excitably. Limit the DSC’s interventions and you’ll discover a slightly challenging uncertainty at the edge of adhesion, although you’ll have to be pushing it to get there. 

For the most part the Convertible is a beguilingly effective road weapon despite the odd hairline crack in its dynamics. It’s worth noting, though, that at £64,000 this car faces some dangerously tempting alternatives. Jaguar F-Type or Porsche Boxster GTS, anyone?