[24] Production of the Gran Coupe models began in March 2012 and ended in September 2018.
[34] Additional options include automatic parking, a Bang & Olufsen surround sound speaker system, and all-wheel drive (xDrive).
[38] Compared to the standard car, the M6 features M-styling, merino leather upholstery, an M-specific head-up display, and a carbon fibre roof.
[39] The Alpina B6 Gran Coupé xDrive was launched in 2014 and is a high performance model based on the 650i.
[40] It shares the 4.4-litre twin-turbo V8 found in the B5 BiTurbo rated at 397 kW (532 hp) and 730 N⋅m (538 lb⋅ft), with a top speed of 318 km/h (198 mph).
[41] B6 models receive 20-inch alloy wheels, aerodynamic elements, and exclusive trim and paint options.
[42] In 2015, the B6 was refreshed and received performance improvements of 59 kW (79 hp) and 70 N⋅m (52 lb⋅ft), and now had a top speed of 324 km/h (201 mph).
[43] The B6 was manufactured alongside the regular 6 Series in Dingolfing, and was then completed with remaining components at the Alpina factory in Buchloe, Bavaria.
However, the B6 is sold by BMW in the United States and Canada alongside BMW's own M6; with the M6 being sportier and more responsive (due to its dual-clutch transmission, turbochargers, and lighter weight being rear-wheel drive only) while the B6 is geared more towards on-road driving rather than the racetrack.