BMW has released a short video showing the inner workings of the new tri-turbo system that the company has implemented in the 3,0-litre straight-six diesel destined for the M550d saloon and other models in the company’s new M Performance Vehicles line-up. At low engine speeds, the first small turbocharger comes into play. Aided by variable turbine geometry, it brings in low-end boost to aid acceleration. The large turbo joins in at medium revs to maximize torque outputs and is then augmented by the second small turbo a higher revs to bring about the engines peak outputs of 280 kW and 740 N.m of torque – enough to propel the M550d xDrive from 0-100 km/h in 4,7 seconds while returning an average fuel consumption figure of 6,3 L/100 km. (Please note: video is purely visual and does not have sound)
It seems that, in a couple of years’ time, all BMW’s M cars will be equipped with turbocharged engines. The latest evidence of this trend is rumours that suggest the next M3 could offer a six-cylinder petrol engine with three turbos. The last time a six-cylinder unit was used in an M3 was in the previous-generation E46, although it was a naturally aspirated unit.