The phrase "hybrid performance car" still carries residual skepticism in some parts of the automotive press. The objections are understandable: early hybrid systems added weight, complexity, and a feeling of disconnect between driver input and vehicle response. The plug-in hybrid system BMW M developed for the G90 M5 addresses each of these objections in turn, and in doing so makes a stronger case for the technology than any press release could.
Architecture: Two Systems, One Character
The M5's powertrain pairs BMW M's revised twin-turbocharged 4.4-liter V8 — producing 584 horsepower on its own — with a 197-horsepower electric motor integrated into the eight-speed M Steptronic transmission. The electric motor is not an afterthought positioned on an axle somewhere down the driveline. It sits in the gearbox housing, which means its torque is delivered to the wheels through the same transmission as the combustion engine. This integration is why the system feels coherent rather than layered.
The 18.6-kWh battery provides up to 25 miles of electric-only range at speeds up to 87 mph. During combined operation, the electrical system performs three functions: it fills the torque gap during gear changes, it provides immediate low-speed response before the V8's turbos build boost, and it enables energy recovery under braking. The net effect on the driving experience is a powertrain that feels stronger and more responsive than a conventional 584-horsepower engine at any speed, in any gear.
Weight Management
The hybrid system adds approximately 290 pounds compared to a theoretical non-hybrid M5. BMW M counters this with extensive use of carbon fiber reinforced plastic in the roof, hood, and front underbody. The front-to-rear weight distribution is 47:53 — better than the previous F90 M5 despite the heavier powertrain. The xDrive system's torque distribution compensates for the additional mass during dynamic driving by applying more torque to the outside rear wheel during cornering, reducing understeer without requiring driver intervention.
The Electric-Only Mode in Practice
In pure electric mode, the M5 is a different car — not a lesser one. The V8 is disconnected, and the electric motor moves two and a half tons with surprising authority. At motorway speeds the car is genuinely quiet, and the electric range is sufficient for urban commuting without engaging the combustion engine at all. This dual character, the ability to be a silent daily driver and a 727-horsepower sports sedan within the same vehicle, is the M5's most commercially relevant quality and its most technically impressive one.
BMW M has stated that future M models will all incorporate some form of electrification. The G90 M5 is the proof of concept. As proof of concepts go, it is convincing.
