This specific use case is applicable exclusively to the United States market. Our conversation with the product manager regarding the BMW XM highlighted an issue of regulatory divergence between the United States and Germany with respect to the state of charge. Unlike the German market where the V8 engine can effectively regenerate the entire battery pack, such is not the case for the American market.
Unlike conventional hybrids, plug-in hybrids typically utilize their internal combustion engines to charge their batteries. However, this is not applicable for the XM, BMW’s first dedicated M car since the M1. The XM, a super SUV, with its lithium-ion battery mounted in the underbody, has a usable energy capacity of 25.7 kWh. Its battery cannot be charged using the V8 engine under the hood.
During an interview with CarBuzz, a BMW spokesperson acknowledged this limitation. The XM’s twin-turbo 4.4-liter gasoline engine is not utilized for recharging the battery due to inefficiencies that would adversely affect fuel economy. Although the combustion engine in other PHEVs can sustain or even increase the current state of charge, in the case of the XM, utilizing the engine to recharge the battery is not efficient.
The XM can be recharged by plugging it in or channeling the energy that would typically be lost during braking into the battery. However, the XM’s curb weight of over 6,000 pounds or more than 2,700 kilograms does not prioritize efficiency. Nevertheless, BMW predicts that the XM can travel solely on battery power for 30 miles (48 kilometers), according to the EPA cycle.
The XM Label Red is anticipated to consume more fuel, considering that its combined output will increase from 644 horsepower and 590 lb-ft (800 Nm) to nearly 750 horsepower and 737 lb-ft (almost 1,000 Nm). The new S68 engine, which is currently found in other BMW models such as the 760i and M60i, as well as the M versions of the facelifted X5 and X6, will power the X7 M60i. Later in the decade, it will also provide the next-generation M5 Sedan and Touring models with a plug-in hybrid configuration adapted from the XM, boasting over 700 horsepower.