BMW unveils lightweight six-cylinder engine

BMW has revealed its new generation 3.0-litre petrol engine, which it claims is the world’s lightest six-cylinder engine.

Weighing 161kg, or 10kg lighter than the current M54 inline six, the high-tech R6 Valvetronic 2977cc engine features a composite magnesium-aluminium crankcase and, producing 190kW (258bhp), is further claimed to have the highest specific power output per litre and the lowest weight per horsepower in its class.

The maximum power output, achieved at 6650rpm, represents a 12 per cent increase on the current engine, while fuel consumption is claimed to be down 12 per cent. Maximum torque is 300Nm, available between 2500rpm and 4000rpm.

Expected to make its first Australian appearance in next year’s new generation E90 3 Series, the engine is the first with BMW’s second generation Valvetronic infinitely variable valve timing technology and is claimed to be the first in the world with an electric water pump.

The pump is controlled solely according to the engine’s cooling requirements, independent of engine speed, and has eliminated the need for a second belt drive. Fuel consumption reduces as a result.

BMW claims the new crankcase is 43 per cent lighter than a comparable cast-iron block and 24 per cent lighter than an all-aluminium crankcase. Structural and torsional stiffness is said to be ensured with the bedplate construction accommodating the crankshaft.

Other systems and components enabling a weight reduction, as well as increased efficiency and performance, include a capacity-controlled oil pump, crankcase with integrally cast gear casing, single-belt drive, magnesium alloy cylinder-head cover and lightweight exhaust manifold.