The convertible will be the third 'M' car BMW has unveiled this year, following the new M3 sedan and M4 Coupe unveiled at the Detroit Motor Show back in January. The three models share the same basic chassis architecture, engine and gearboxes.
The M4's engine is a brand new 3.0-litre turbocharged straight six, which seems similar on paper to the unit found in lesser 435i models, but uses all new internals and a different turbo setup which allows it to produce some serious grunt. Peak power is 317kW and torque is a substantial 550Nm.
Compared to the 4.0-litre naturally aspirated V8 of the old M3 Convertible power is up 8kW but torque has swelled by 150Nm which should equate to more accessible performance. The new model is also more fuel-efficient than its predecessor with 9.1L/100km possible in the manual car or 8.7L/100km with the automatic gearbox.
While lighter than the old V8 M3 Convertible by around 60kg, the new M4 Convertible still isn't a lightweight. The new car weighs 1750kg or around 250kg more than its coupe sibling. Still, BMW claims the M4's suspension has been tuned for maximum precision and response, and in terms of straight-line acceleration this convertible is more than brisk.
Zero to 100km/h takes 4.6 seconds with the DIY manual gearbox – that can automatically blip the throttle on downshifts - or 4.4 seconds if you option the quick-shifting seven-speed dual clutch transmission – around 0.8 seconds quicker than the old M3 Convertible.
In terms of styling the M4 Convertible is noticeably more sporting than lesser 4 drop-tops. The 'M' car receives an aggressive front bumper with some big gaping air intakes, a heavily contoured bonnet, wider front and rear fenders, the former featuring aerodynamic gills, and the rear bumper houses quad exhaust tips. You'll also spot new wheels, colored brake calipers and new mirror caps.
Inside the upgrades include sports seats with special 'M' badging and an M-specific steering wheel. There is also some leather-look material placed over the dashboard and center console, though we suspect this will feature on the updated 3 Series which is due to be released later this year.
The electrically operated metal folding hardtop takes 20 seconds to lower, and this can be done at speeds of up to 18km/h. With the roof stowed away, boot space shrinks from 370-litres to 220.
The M4 Convertible will make its public debut in New York later this month before heading our way late this year or early 2015.