The B5 BiTurbo Edition 50 was launched in March 2015 at the Geneva Motorshow to celebrate the 50th anniversary of Alpina. This model is based on the Sedan and Touring versions of the B5 BiTurbo, complimented with parts unique to this model.

Available colors were Black Sapphire, Mineral White, Alpina Blue II, Alpina Green II and BMW Individual Sepia.

Production was limited to 50 units. The last example of the B5 BiTurbo Edition 50 was delivered in April 2016.

In addition to the B5 BiTurbo Edition 50, Alpina also offered the B6 BiTurbo Edition 50.

The B5 BiTurbo Edition 50 engine is an upgraded version of the B5 BiTurbo. Extensive optimisation of the air intake ducting and air filter housing lead to a substantial reduction of losses which together with an uprated fuel supply system resulted increased output of 60 hp from previously 540 hp.

A titanium exhaust with carbon trim from Akrapovič offers a weight reduction of 17kg on the standard B5 BiTurbo exhaust. The system features an active exhaust valve.

A limited slip differential from Drexler is installed.

The suspension setup is similar to the regular B5 BiTurbo, but the chassis settings are adapted slightly to the wider wheels.

Especially for the Edition 50 models, a new brake system with blue calipers and revised rear axle components including larger discs was installed. Optionally, a high performance brake system for the front axle was available. Featuring 4-piston fixed calipers from Brembo with 395 mm discs and high temperature resistant pads.

Also unique to the Edition 50 models are forged aluminium wheels, which provide greater stiffness and strength compared to conventional cast aluminium alloy. This allows distinguishing side-cuts (material reduction) on each of the twenty spokes, resulting in a total weight saving of 15.6 kg. This weight reduction is despite the wheels having increased in width by half an inch to measure 9×20“ front and 10×20“ rear.

As standard the Edition 50 models featured extended Nappa leather interior including a leather instrument panel, ceramic finish for controls, an anthracite headliner and exterior trim in high-gloss Shadow Line.

As an option unique to Edition 50 models, a Heritage interior in Lavalina leather was offered. The design is reminiscent of the iconic B7 S Turbo Coupé upholstery from 1982. The interior features black seats combined with seat and backrest centres in Forest Green with chequered yellow/black stitching.

Piano black trim with Edition 50 lettering and a personal signature by Burkard Bovensiepen, the founder of the company in 1965, are also unique to the Edition 50.

Other unique details include stainless steel door finishers with Edition 50 lettering and metal emblems in the seatbacks and floor mats with an engraving showing the years 1965 – 2015 in reference to Alpina’s 50th anniversary.

The production number of each Edition 50 model is shown on the production plaque and on the reverse of the key ring.

Acceleration from 0-100kph is 4,2 seconds.

Top speed for the sedan was 328kph and 323kph for the Touring version.