BMW’s triple-turbo diesel engine remains one of the most unusual performance diesels ever produced, delivering 381 horsepower and 541 lb-ft of torque while combining strong performance with diesel efficiency. The N57S engine powered several BMW models in Europe but was never offered in America.
BMW’s Rise Into Performance Diesels
From the 2000s through the mid-2010s, diesel engines were a major presence on European roads, powering everything from subcompact hatchbacks to luxury sedans. Their combination of performance and efficiency helped make them especially appealing to buyers at the time.
BMW joined other automakers in developing high-performance diesel engines. Its 535d helped bring faster diesel models to more parts of the BMW lineup after diesel V8s had been reserved for the 7 Series.
The 535d used a version of BMW’s M57 inline-six with two turbochargers, producing 282 horsepower and 428 lb-ft of torque. The engine was later used in models including the X5, X3, 3 Series and 6 Series.
The Only Production Tri-Turbo Diesel
The 35d eventually evolved into the N57 inline-six, but BMW went further with the N57S. Rather than adding more cylinders or simply using larger turbochargers, BMW added a third turbocharger.
The result was a production triple-turbo engine designed for mass production. The N57S produced 381 horsepower and 541 lb-ft of torque, giving it more torque than a contemporary M5, which produced 502 lb-ft.
The triple-turbo diesel debuted in 2012. The third turbocharger was primarily intended to reduce turbo lag while also increasing power.
Which BMW Models Used the Engine?
The N57S powered several high-performance BMW models. It was offered in the F10 M550d xDrive sedan and F11 M550d xDrive Touring wagon, as well as the E70 X5 M50d and E71 X6 M50d.
The engine continued into the succeeding generations of the X5 and X6, the F15 and F16, respectively. It was also used in the F01 750d xDrive and F02 750Ld xDrive, which were not M Performance models.
According to BMWBlog, the engine helped launch what is now known as M Performance, the junior counterpart to BMW’s M Division. The lineup later included models such as the M340i, M240i and X3 M50.
A Remarkably Complex Diesel
The triple-turbo setup required an intricate arrangement of components, with each stage of the turbo system working together to deliver the engine’s performance. Maintaining multiple turbochargers also added to the engine’s complexity.
The N57S was developed at a time when hybrids were still viewed primarily as tools for improving efficiency rather than increasing performance. Today, hybrids and plug-in hybrids provide another route to combining power and efficiency.
The Triple-Turbo Diesel Was Never Sold in America
Despite its performance, the N57S was never made available in America. That means anyone in the U.S. who wants to import one will have to wait until 2037 before the engine becomes eligible for import.
For now, BMW’s triple-turbo diesel remains a distinctive chapter in the company’s performance-engine history, with the M550d Touring standing out among the models that used the 381-horsepower engine.
