BMW to launch 300kW quad-turbo diesel

BMW will replace its current tri-turbocharged 3.0-litre turbo-diesel with a new 3.0-litre powerplant featuring an additional -- fourth -- turbo, it has been revealed.

Set to go on sale next year under the bonnet of the soon-to-be-launched BMW 7 Series, the new diesel will power a new, sportier version of the luxury limousine called the M750d, according to British mag, Autocar.

Producing at least 300kW/800Nm, the new quad-turbo diesel is also expected to go on to power the all-wheel drive version of the 5 Series and X5/X6 SUVs.

It’s not yet known how the new engine will incorporate its fourth compressor, with some suggesting the quad-turbo engine could be a development of the old tri-turbo 3.0-litre straight-six but, instead of a traditional exhaust-driven blower, the range-topping diesel could get a small, electric-motor driven turbo.

If that’s the case the e-turbo will be powered by its own lithium-ion battery that recovers energy under braking. The benefit of an e-turbo is that it can deliver its maximum boost from idle, offering sharper engine response, better performance off the line and increased efficiency.

The previous 280kW 3.0-litre tri-turbo developed its mighty 740Nm of torque at a relatively high (for a diesel) 2000rpm. Whether the new car gets e-boost or not, engineers will be keen to lower that torque peak for stronger performance down low. BMW will also improve on the M550d’s 6.3L/100km fuel consumption.

BMW is expected to reveal more technical information about its new quad-turbo diesel at the Frankfurt motor show in September.