When it debuts in the 750d model, the quad-turbocharged inline-six will produce 395 horsepower, according to BMW Blog. That’s compared to the 381 hp of the triple-turbocharged 3.0-liter inline-six offered in Europe on the outgoing generation of 7 Series. That engine also produces 546 pound-feet of torque.
The new engine will reportedly be called either B57 TOP or B57S, and could be offered with BMW’s xDrive all-wheel drive system, as in the 740Ld xDrive currently sold in the U.S., and an eight-speed automatic transmission. A previous report said it could produce 408 hp and 590 lb-ft of torque, so this latest figure represents a bit of a downgrade in expectations.
No technical details of the quad-turbo engine have been released so far, but there is speculation that it could employ a mix of exhaust-gas driven and electric turbochargers. This could give the engine a more user-friendly powerband by spooling up the electric turbos at lower speeds to cut lag, and allowing the conventional turbos to take over at higher rpm.
The new diesel engine is expected to debut on the 750d xDrive at the 2016 Geneva Motor Show in March. It could eventually find its way into diesel versions of the 5 Series, X5, and X6 as well. All of these models are currently offered as more powerful “50d” variants in Europe, where diesels are much more popular than in the U.S.
Since diesels aren’t quite as common on this side of the Atlantic, it’s unclear whether BMW will offer its new quad-turbocharged engine here, or whether it will become one more piece of automotive forbidden fruit.
