The B12 5.7 Coupé is one of the fastest cars Alpina have ever produced. It is based on the BMW 850CSi which was presented in late 1992 and the B12 5.7 Coupé was introduced about a half year later. Alpina admitted that with the 850CSi, BMW Motorsport did a terrific job so the B12 5.7 Coupé is just an enhancement of the 850CSi.

The B12 5.7 Coupé engine is based on the BMW Motorsport prepared 5,6 litre V12 which produces 380 bhp in stock form. Alpina modified the engine capacity to 5.7 litre, modified the intake, crankshaft and camshafts. A new exhaust system is used with Alpina´s own stainless steel catalytic converters and Motronic engine management system was reprogrammed. These changes result in 416 bhp and 570 Nm of torque.

The gearbox is a Getrag 6-speed manual as standard however the the B12 5.7 Coupé had an interesting option, the Shift-Tronic system. That is a electronic clutch management system developed by Alpina in conjunction with LUK GS and is the only Alpina ever offered with this system.

BMW Motorsport was so close to the preferred Alpina specifications with the 850CSi suspension that Alpina only changed the front springs to lower the nose a little.

The brakes are the same as the 850CSi however the wheels are bigger; 18″ with 245/40 front and 285/35 rear tires.

As standard the B12 5.7 Coupé has anthracite leather with blue and green stripes. A new leather-covered steering-wheel is fitted, as is a wood gearknob. The B12 5.7 Coupé has the same exterior changes as the 850 CSi. Unique for the B12 5.7 Coupé is the carbon-fiber bonnet with NACA duct in the center and engine vents on the sides.

Alpina claim a 0-100 km/h time of 5,8 seconds, 0-1000 m in 24,9 seconds and a top speed of more than 300 km/h.

A total of 57 B12 5.7 Coupé were built.