07 Mar 08
BMW is showing the Vision EfficientDynamics hybrid car at Geneva.
The Vision EfficientDynamics show car, a prototype X5 hybrid, combines a twin-turbo, four-cylinder 2.0-litre diesel engine (204bhp/295lb ft), an all-new eight-speed automatic transmission and an alternator-generator system to return 43.5mpg and 172g/km - not bad for a large SUV. Performance is still strong: 0-60mph in 8.9 seconds.
The electrical power is generated from energy that would otherwise have been lost during deceleration. That energy is collected and stored in batteries installed in the boot.
Extra energy comes from roof-mounted solar panels and that is used to pre-heat the diesel fuel for a more efficient start-up.
The alternator is integrated into the engine's crankcase rather than driven from the front of the engine, and a pint-sized generator - producing up to 20bhp on demand - is mounted directly onto the gearbox.
A 120-volt power system runs in parallel to the 12-volt network, and the energy captured from engine overrun is used to power the air conditioning, coolant pump and power steering system.
The eight-speed gearbox offers improved fuel consumption and lower emissions.
Consumption and emissions are also enhanced by a lower ride height and by aerodynamically-improved 19-inch wheels.
Check out the rest of our Geneva Motor Show coverage.
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Feature: BMW's Efficient Dynamics
