At the 2012 Geneva Motor Show, BMW will introduce the first four models in the new product line - BMW M Performance Automobiles – BMW M550d xDrive (sedan and touring), BMW X5 M50d and X6 M50d. The high performance diesels are powered by the same tri-turbo engine.
A new video gives us a visual of the technology behind BMW’s first tri-turbo diesel engine which is based on the popular 3.0 liter inline-six (N57D30), but with an extra turbocharger. The innovative powerplant produces 381 horsepower and 740 Nm (546 lb-ft) of torque.
With 93.6 kW/127.3 hp per liter of displacement, the N57 sets a new benchmark standard for diesel engines. To achieve this goal, BMW has not only added a third turbocharger, but also engineered a new aluminum crankcase, common-rail direct injection with piezo injectors and high-pressure turbocharges with variable turbine geometry. The maximum injection pressure is 2,200 bar.
The size, arrangement and interplay strategy of the three turbos are designed to guarantee maximum power delivery across a wide rev band. The system comprises two relatively small turbochargers and one large turbo, which join forces precisely to deliver the amount of power required. According to the driving situation, the low moment of inertia of the small turbochargers is exploited to the full to deliver razor-sharp responses, while the link-up with the large turbo is maximized to generate as much charge pressure as possible.
The diesel technology developed exclusively for the BMW M Performance Automobiles also offers increased fuel economy. The M550d Sedan offers fuel economy figures of 6.3 liters per 100 kilometers in the EU test cycle, while the Touring achieves 6.4 l/100 km. CO2 emissions are 165 grams per kilometer for the BMW M550d xDrive Sedan and 169 g/km in the case of the BMW M550d xDrive Touring.