A range of BMW diesel models will be equipped with mild hybrid power systems as standard from spring, promising improved fuel economy and reduced emissions.
All 320d models, including the four-wheel drive xDrive variants, the X3 xDrive20d and X4 xDrive20d – powered by the same 2.0-litre turbocharged diesel engine – will gain a 48v starter-generator and additional battery for an 11bhp power boost, regenerative braking capabilities and an improved coasting function.
The small generator is said to improve acceleration from a standstill, and can be used at speed to reduce fuel consumption. It will also allow for smoother restarts in traffic and at junctions.
Regenerative deceleration works by disconnecting the combustion engine at speeds of under 9mph, recuperating kinetic energy as the car coasts to a stop. Similarly, at speeds of up to 99mph, the coasting function now disconnects the diesel motor, rather than switching it into idle.
BMW claims the system, as well as offering tax and environmental benefits, ‘enhances both efficiency and dynamics’ of the updated models.
Alongside the roll-out of mild hybrid technology, BMW has introduced a new diesel-powered version of its 1 Series hatchback. The 120d uses a turbocharged 2.0-litre four-cylinder producing 187bhp to accelerate from 0-62mph in 7.3 seconds, and on to a top speed of 144mph. Power is sent to the front wheels through an eight-speed automatic gearbox.
The petrol-powered 318i has been updated as well, swapping its three-cylinder engine for a 2.0-litre four-cylinder unit that pumps out 154bhp and 184lb ft. The 318i saloon will now accelerate from 0-62mph in 8.4 seconds and reach a top speed of 139mph.