For the most part, BMW has always distinguished its M division models with unique engines; Engine that is only available in the right M car. Over the years there have been some exceptions – such as the BMW 1M that used the Z4 to N55 engine – but, in general, M cars have the M engine. However, this new M Division engine, dubbed the “S68”, will actually be used more than the front-facing M car. While it is still a valid M engine, it will also be used in several upcoming M performance cars.
At a recent event, seeing the new BMW X7 LCI in metal, we learned a lot about the new S68 engine, what sets it apart and why it is only being used in M cars.
What is S68 engine?
On paper, the new S68 may not look as different as the old S63, which powers all current V8 M cars. Like the old S63, the new S68 is another 4.4 liter twin-turbocharged V8 with a hot-V design. On the BMW X7 M60i, it produces 530 horsepower, which is only seven horsepower compared to the standard N63 powered by the pre-LCI X7 M50i.
However, there is literally no carrying part from the S63 engine to the S68. It’s a completely new engine, only its displacement and Hot-V design are the same.
What makes it different?
For starters, the S68 is literally different from the S63. However, the main updates are a new crankshaft, oil cooler, oil sump, upgraded turbocharger and even a new electric van system – the first, because all previous vanes systems worked off the oil pressure.
What makes it even better is the 48-volt light-hybrid system. Although the S68’s Mild Hybrid (MHEV) system is different from other BMW MHEV systems. Instead of a small electric motor attached to the engine’s crankshaft to add some power to smooth the turbo lag, this new electric motor is actually built into the transmission and can deliver its power directly to the powertrain.
Since it’s built into the transmission itself, the X7 M60i and all subsequent S68-powered cars can now go somewhat better off the coast via its auto-start / stop, as well as better restart the light set. It uses a 48-volt electric motor to start the engine when it is hot. There is still a 12-volt battery for cold start but all other start will use 48-volt systems and electric motors.
Interestingly, the transmission is also new. It’s still a ZF eight-speed unit but it’s designed to handle a completely new, 48-volt light hybrid system.
Why is M Division engine used in non-M vehicles?
So everyone here wants to know the answer to the big question. BMW is using this new M Division-designed and built S68 engine in technically less cars for two reasons. One is that an actual M engine ditched M performance gives cars more character and more fun. The nature of the BMW X7 changes when you get on the M60i and get that suitable motorsport-type engine. And the same goes for all the other V8-powered M performance models moving forward.
Another reason, and it has not been officially stated, but the release is not difficult. The BMW N63 and its S63 siblings are becoming unusable due to the strictness of Euro 7 emissions rules. So BMW needed a new engine for those cars, as well as for its M cars. Instead of building two completely-new engines, one for the X7 M60i and one for other appropriate M-division products in the future, it would be easier and cheaper to build one engine and detonate it for lesser models.
M engine for the public
All this means we will have M performance models that will use the right M division engine, which will give them much more enjoyable features. That engine and brand thin? According to a couple of different BMW representatives, neither would it. The M versions of the S68 will be a bit unique; Their own power, performance, tuning, response and even electrification in some cases such as BMW XM.
Whether you agree with BMW or not, the reality is that more and more customers will have access to the original M division engines.