Start with what the Alpina B4 is: a 2-door coupé / 2-door retractable hard-top convertible / 4-door saloon with 3.0 L BMW N55 twin-turbo Straight-six engine, built from 2014 to 2025, as electrification stopped being an experiment and the crossover took every market. What it meant takes a little longer.
How it came about
The Alpina B4 and Alpina D4 are high-performance compact executive cars manufactured by the German automobile manufacturer, Alpina. Based on the BMW 4 Series, the B4 and D4 are manufactured in coupé and convertible body styles. The first generation B4 and D4 were launched in 2014 and the more powerful B4 S was launched in 2017.
The hardware
The engine is 3.0 L BMW N55 twin-turbo Straight-six engine; other versions carried different engines, listed in the specification table below. On the scales it comes to 1690 kg. Drive goes through a 8-speed ZF 8HP70 automatic. The wheelbase is 2810 mm. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
Family and rivals
In the Alpina line-up the Alpina B4 has a clear place: it replaced the Alpina B3 (E90); the factory was Buchloe, Germany. The cars a buyer would have weighed it against include the Chevrolet Camaro, the Ford Escort, the Ferrari 488. Its Alpina stablemates include the Alpina B10 and the Alpina B10 (E39).