BMW hybrid supercar signposts the future

High-tech vision: BMW makes it plain that fuel-efficiency need not mean an ugly vehicle. Photo / Supplied

A racecar-inspired hybrid uses two electric motors, one diesel for blistering performance.

Now, a plug-in BMW. And the company has chosen to introduce the technology not in a boring city-car concept, but the wild 2+2-seat Vision EfficientDynamics (VED) super-coupe.

It's meant as a signpost to BMW's future sustainable mobility strategy and is far from being a prototype of a production car.

The show vehicle is said to have M-car performance and fuel consumption as good as a small hybrid. BMW quotes a 0 to 100km/h acceleration time of 4.8 seconds and an electronically limited top speed of 250km/h.

Carbon dioxide emissions are said to be 99g/km, or 50g/km on the EU electricity mix cycle.

BMW is not alone in the quest for a hybrid supercar. Among others, rivals Audi and Mercedes are developing vehicles to meet the same market segment.

The groundbreaking VED uses an aluminium spaceframe chassis and variable-transparency polycarbonate glass panels.

Formula One racing cars inspired the styling.

It follows the earlier mild-hybrid diesel-electric X5 Vision concept shown at Geneva last year and is said to incorporate "design language" for BMW's rumoured Z10 ED electric supercar that may appear in about five years.

The car is principally powered by two electric motors drawing on a lithium-polymer battery pack comprising 98 cells with plug-in recharging now being favoured by a number of manufacturers.

Its battery pack can also be charged by a common-rail direct-injection 1.5-litre three-cylinder turbodiesel ahead of the rear axle. BMW is widely thought to be readying an engine of this type for general production for both the next 1-Series due in two years and the 3-Series.

The Vision's diesel is said to produce 120kW of power and 290Nm of torque, outstanding figures for a three-cylinder motor.

A rear-mounted electric motor develops a constant 25kW and a maximum of 38kW to provide either assistance or full electric driving. A front synchronous motor puts out 60kW and peak torque of 220Nm, with an extra 84kW available for up to 30 seconds and 104kW for up to 10 seconds.

Power is transmitted through a two-stage, single-speed reduced-ratio gearbox that lets the car run on just electric power, just diesel, or an infinite combination of both.

There's also a thermo-electric generator able to develop up to 200W by converting thermal energy from exhaust emissions into electric power.

With the help of regenerative braking and an idle-stop function, the Vision has an electric-only range of 50km and a total driving range of 700km.

Meanwhile, more than 25 models in the BMW lineup are being replaced with more fuel-efficient alternatives using aspects of the corporate EfficientDynamics technology.

New Zealand is to be one of the first countries outside Europe to introduce the fuel savers.

Expect to see them from around November.