The G1 engine is based on the M57D30 single-turbo diesel engine from the BMW 530d with 190PS (142kW) and 410Nm. From 1999 to 2002, this BMW engine was winner in the prestigious International Engine of the Year awards.

The G1 engine was introduced in the E39 D10 BiTurbo in late 1999. It was the first diesel engine for Alpina. Development as presented as a joint project between BMW and Alpina.

Modifications include custom engine block, cilinderhead, pistons, exhaust and intake manifolds, turbochargers, exhaust, intercooler and high-pressure fuel pump. Extensive modifications were also made to the cooling system.