The B6 BiTurbo Gran Coupe is based on the 650iX Gran Coupe.

In March 2014, at the Geneva motorshow, the B6 BiTurbo Gran Coupe was introduced, available only as 4WD Allrad version. This model is the fastest Alpina model produced to date.

In March 2015, the LCI version of the B6 BiTurbo Gran Coupe was introduced.

Production of the B6 Gran Coupe ended in summer 2018 due to the F06 6-series being phased out by BMW.

The engine in the B6 BiTurbo was initially introduced in the B7 BiTurbo. It is based on the BMW 650i engine, with custom Alpina engine block, cylinder heads and internal parts. It has been modified to 540hp and 730Nm. Heat management is improved by installing custom Alpina cooling package with radiator, engine oil cooler, transmission oil cooler, as well as extensive custom Alpina air ducting and intercooler. Also, an additional electric water pump is installed.

From late 2015, the B6 BiTurbo engine was upgraded to 600hp and 800Nm.

The B6 BiTurbo Gran Coupe has a stainless steel exhaust from Boysen.

The only available gearbox is the 8-speed Sport-Automatic transmission (ZF 8HP70) with Switchtronic.

The B6 BiTurbo suspension is based on the 650i, modified with Alpina settings and springs. The wheel carriers are heavy-duty items sourced from the BMW 7-series. The driveshafts are custom Alpina parts.

A custom Alpina crossbar is installed at the rear.

Wheels are 20-inch Alpina Classic wheels with 255/35 and 285/30 Michelin Pilot Super Sport tires.

The front brakes are sourced from the high-speed version of the F01 750i. The rear brakes are from the 650i.

The B6 BiTurbo undergoes the same interior changes as usual with Alpina. Cluster gauges are custom Alpina with classic blue background combined with steering wheel trimmed in Lavalina leather. Additionally, interior trim is fine Alpina wood or piano lacquer with Alpina logos. A no-cost option are Alpina badges in the seats. Optionally, a custom interior in Lavalina leather can be ordered.

For the exterior, the changes are limited to an Alpina frontspoiler with carbon splitters, rear spoiler, rear diffusor and Alpina badges on the rear. A non-cost option is the classic Alpina decor on sides of the car and frontspoiler. Available exterior colors include Alpina Blue and Alpina Green II.

Acceleration from 0-100kph is 4,0 seconds.
For the 600hp version, this reduced to 3,8 seconds.

For the initial 540hp version, top speed was 314kph.
With the 600hp version, this increased to 324kph.