Announced at the same time as the pricing for the new 2 Series Active Tourer and new engines for the 5 Series, the changes for the 4 Series Convertible mean that the number of engine variants available will increase from five to nine. 

The new BMW 420i Convertible will form the entry-level model, with a 2.0-litre petrol engine featuring BMW TwinPower Turbo technology that produces 181bhp and a peak torque of 199lb.ft. This provides acceleration from zero to 62mph in 8.2 seconds, with an average fuel consumption of 42.8mpg and CO2 emissions of 154g/km. It costs from £34,210 OTR.



Three additional diesel engines with BMW TwinPower Turbo technology are available. The BMW 425d Convertible's 2.0-litre four-cylinder engine features multi-stage turbocharging and common-rail direct injection, giving 215bhp and a maximum torque of 332lb.ft. The result is zero to 62mph in 7.3 seconds and an average fuel consumption of 54.3mpg and CO2 emissions of 138g/km.



From the summer of 2014, the 425d will be joined by two new straight six-cylinder diesel engines featuring BMW TwinPower Turbo technology. The BMW 430d Convertible features a turbocharger with variable turbine geometry and common-rail direct injection with solenoid valve injectors, giving a maximum output of 254bhp and a maximum torque of 413lb.ft. The model, which is equipped as standard with an eight-speed Sport automatic transmission, accelerates from a standstill to 62mph in 5.9 seconds. The average fuel consumption is 53.3mpg with CO2 emissions rated at 139g/km.



The flagship model, the BMW 435d xDrive Convertible, is only available with four-wheel-drive and uses multi-stage turbocharging and common-rail direct injection with piezo injectors. Power is 309bhp with a peak torque output of 465lb.ft. Also offered with an eight-speed Sport automatic transmission as standard, the model takes 5.2 seconds to accelerate from zero to 62mph. Average fuel consumption is 49.6mpg with CO2 emissions of 151g/km.



The new BMW 4 Series Convertible diesel models cost from £38,540 OTR for the 425d SE Convertible, £44,485 OTR for the 430d Luxury Convertible and from £48,400 for the 435d xDrive Luxury Convertible.



The 4 Series Gran Coupé also gains new engines and additional models. Four additional model variants are added, three of which feature BMW’s xDrive all-wheel drive system. These include the BMW 420i xDrive Gran Coupé, with its 181bhp four-cylinder petrol engine, which offers a 0-62mph time of 7.6 seconds along with average fuel consumption of 40.9mpg and CO2 emissions of 161g/km. The 420i xDrive Gran Coupé costs from £30,960 OTR.



The new BMW 430d Gran Coupé is available in both rear and four-wheel-drive form. The straight six-cylinder diesel engine develops 254bhp and is mated to an eight-speed Sport automatic transmission on both models. This enables the rear-wheel-drive variant to accelerate from zero to 62mph in 5.6 seconds, while the BMW xDrive variant takes 5.3 seconds.

For economy figures, the BMW 430d Gran Coupé returns a fuel consumption of 55.4mpg (53.3mpg with xDrive) with CO2 emissions of 134g/km (140g/km with xDrive).



Finally, the new BMW 435d xDrive Gran Coupé delivers 309bhp, and is only available with xDrive and the eight-speed Sport automatic transmission. It takes 4.8 seconds to sprint from zero to 62mph, with average fuel consumption of 50.4mpg and a CO2 emission rating of 146g/km. It is priced at £44,545 OTR in Luxury trim.