According to reports, the BMW system will use cylinders one, two and three to generate boost for one turbine, while cylinders four through six will power another turbocharger, just like on the current 3.0-litre twin-turbo BMW models.
A third unit reportedly in development will be an electrical turbo which will provide either additional boost low down in the rev range - to eliminate turbo lag - or high up in the rev range, leaving two small conventional turbochargers with the job of eliminating lag. The unit is speculated to produce between 255kW and 295kW.
According to various international reports, the tri-turbo diesel engine will debut on the 2012 model BMW 7 Series and X6 SUV vehicles in '30d' guise. The cars and the engine are also said to make a debut at this year's Frankfurt Motor Show in September.
These are just rumours at this stage so we'll have to wait and see. What do you think, does it seem like a good idea or is three turbos too many?