The new BMW M4 Convertible goes on sale this September, with prices starting from £60,730.
The M4 Convertible features a wider body and a longer wheel-base than its M3 Convertible predecessor.
Its three-part folding metal roof is both quieter and warmer in winter, and may be folded away completely in 20 seconds, a surgical procedure that can be performed at speeds of up 8 mph.
A six-second ‘loading’ mode offers greater access, although the boot offers 370 litres of space, falling to 220 litres with the roof folded.
Power comes from the identical 3.-litre in-line six-cylinder twin-turbo engine as the M3 M4 and Saloon Coupe.
This unusually high-revving unit has a 7,600rpm red-line and develops 550Nm and 431hp of torque, enough to get the -62mph sprint in 4.4 seconds when mated on the seven-speed dual-clutch transmission, or 4.6 seconds having a conventional manual ‘box. Top speed is electronically confined to 155mph.
This level of power necessitated the application of additional water, engine oil and transmission oil coolers, plus an electric coolant pump to help cool the turbocharger bearings when the car goes to a stop.
A six-speed manual transmission is standard, even though the M DCT unit is really a £2,645 option that enables gear-shifting either via the gear lever or steering wheel-mounted paddles, and boasts a launch control feature.
BMW say the usage of aluminium for the bonnet, front wings along with other components, plus the selection of a carbon-fibre reinforced plastic propeller shaft and strut brace, have led to a 60kg weight reduction compared to the old M3 Convertible.
This weight reduction, plus the use of aerodynamic measures including the smooth underbody and special airflow channels at the front, are said to be key contributors for the M4’s economy figure of 32.5 mpg and CO2 emissions of 203 g/km (31 mpg and 213 g/km for manual models).
Obviously, the M4 Convertible’s focus is around the driving experience rather than its eco-credentials, and also the M4 uses a double-joint sprint strut suspension at the front and an aluminium five-link axle at the rear.
An Energetic M Differential helps keep all things in check, especially when accelerating hard out of corners, and can provide a variable degree of lock approximately 100% when required.
All UK models will be fitted with Adaptive M suspension as standard, and this offers a choice of Sport, Comfort and Sport modes that also change the settings for that electro-mechanical steering rack.
UK standard specific will also include 19-inch light alloy wheels, BMW Professional infotainment system, front and rear parking sensors, folding door mirrors and heated leather seats.