The BMW S68 is BMW M's newest M-developed 4.4-liter twin-turbo V8, introduced in 2022 and built around a 48-volt mild-hybrid architecture. Replacing the long-serving S63 in M's flagship lineup, the S68 marks a significant step forward: it not only serves as a stout stand-alone powerplant but also forms the combustion heart of the plug-in hybrid drivetrain in the sixth-generation G90 M5 and the XM.
What the S68 Is
The S68 is a "hot-vee" V8 — its twin turbochargers sit inside the 90-degree valley between the cylinder banks for compact packaging and sharp throttle response. Displacing 4.4 liters, it pairs forced induction with a 48V mild-hybrid system that adds torque fill, smooths stop/start operation, and improves efficiency. It revs to a 7,200 rpm redline, giving it an appetite for high-rpm work that belies its considerable low-end grunt.
Engineering & Specs
- Configuration: 4.4L twin-turbo V8 with 48V mild-hybrid assist
- Output: 523–577 hp depending on application
- Torque: 553–590 lb-ft
- Redline: 7,200 rpm
- Production: 2022–present
Compared with the naturally aspirated M V8s of the past — such as the S65 that powered the E90/E92 M3 and the exotic S85 V10-derived family — the S68 trades screaming induction sound for tremendous flexibility and effortless force. The 48V system is the key differentiator, enabling the electrified performance that defines BMW's current flagship M cars.
Which BMWs Use It
The S68 appears across BMW's most powerful modern models:
- G90 M5 — combustion half of the M5's PHEV system
- XM — BMW's dedicated M plug-in hybrid SUV
- X5 M / X6 M (LCI)
- X7 M60i
Not sure which V8 lives under your hood? Run your chassis number through our VIN decoder to confirm the exact engine and specification.
Ownership & Buying Notes
As a current-production engine, the S68 has no meaningful long-term reliability history yet, and most examples remain under factory warranty. Buyers should follow the same fundamentals that apply to any modern turbocharged M engine: adhere strictly to oil-service intervals, allow the turbos and 48V system to warm and cool properly, and keep software up to date at the dealer. Given the added complexity of the mild-hybrid electronics — and the full PHEV hardware in the M5 and XM — professional BMW service is strongly recommended.
Enthusiasts cross-shopping older M metal often compare the S68 against turbocharged inline-sixes like the S55 or the classic naturally aspirated S54. Each represents a distinct era of M philosophy; the S68 defines the electrified present. Learn more in our BMW engine encyclopedia.
Legacy
The S68 signals where BMW M is headed: massive output paired with electrification, without abandoning the emotional character of a high-revving twin-turbo V8. As the powerplant behind the M5 and XM, it is arguably the most important M engine of the 2020s.