The Alpina B6 (E30) is Alpina's six-cylinder line built on the E30 3 Series between 1984 and the end of E30 production. Three variants are the collector story: the B6 2.8/1, based on the E30 323i / 325i with a 210 hp Alpina six, Girling front brakes and a 230 km/h top speed (259 built); the B6 3.5, based on the E30 325i with Alpina's 3.5-litre six producing 261 hp (254 hp with catalyst) and 346 Nm through a Getrag five-speed manual on Bilstein suspension with 16-inch Alpina wheels and Recaro buckets (0–100 km/h in 6.6s); and the halo car, the B6 3.5 S, built on the E30 M3 chassis with the 254 hp Alpina 3.5-litre six and a dogleg five-speed 'sportgetriebe', good for 251 km/h — faster than BMW's own M3 Sport Evolution.
All three are factory Alpinas, sold and titled as Alpinas with their own chassis numbers and factory documentation — not tuner conversions.
The B6 3.5 S is widely rated among Alpina's finest ever cars: an E30 M3 chassis paired with the smooth, high-torque Alpina six that BMW never built. Its only chassis difference from a standard E30 M3 is the stiffer A/C-spec front springs. Alongside the B6 2.8/1 and B6 3.5, it completes an E30 line that answered the M3 in an entirely different register — six-cylinder torque and Continental GT manners against BMW's homologation four. All three sit at the intersection of the E30 M3 market, the wider Alpina programme and the youngtimer German car re-rating of the last decade.
