The M440i has a new variation of the B58 twin-turbo 3.0-liter six-cylinder engine with mild-hybrid assist. It has an 11-horsepower boost from the e-motor, but there’s a bit of a twist. Technically, the outputs have grown to 386 hp and 398 lb-ft, up from 382 hp and 369 lb-ft.
As it turns out, this was the M440i’s output all along. From March, M440i models have been equipped with a new KSG crankshaft starter generator. It can deploy the additional power of the MHEV system for longer than 10 seconds, which means BMW can now claim it as the standard output under existing homologation laws.
BMW provided updated acceleration figures, but only in global markets. Its mild-hybrid system provides enough power to get the M440i xDrive to 62 mph in 4.5 seconds. This matches the time BMW claimed when the current generation 4 Series was launched in 2021.
Therefore, we expect the new M440i xDrive to match the old car’s time of 4.3 seconds. While the outputs are now technically higher, the older mild-hybrid system provided just enough juice for the 0 to 60 sprint.
Interestingly, if you look at the table below, you’ll see maximum power arriving 300 rpm earlier than before, while the maximum torque kicks in 100 rpm later. That’s not something the average person will notice.
