2023 BMW Alpina B4 Gran Coupe Spy Shot

Alpina is developing a new generation B4 based on the latest BMW 4 Series, as evidenced by prototypes spotted in Germany.

While the previous B4 was based on the 4 Series Coupe, the new model will be based on the more practical 4 Series Gran Coupe hatchback. This should boost its popularity in the key markets of China and the US (if it ends up here), where coupe sales are typically lower.

The 4 Series Gran Coupe was unveiled in June, and the first models have just arrived at dealers nationwide. The Alpina version is at a very early stage of development and will take at least a year to complete. The only changes seen on the prototype are Alpina-style exhaust tips, a new rear fascia and possibly an Alpina brake package. More advanced prototypes should get a new front end and side skirts.

The mechanicals are expected to follow the Alpina B3 package based on the 3 Series. This means that the powertrain will be a turbocharged 3.0-liter inline six-cylinder engine normally found in the M440i. Unlike the standard 382 hp and 364 lb-ft, the Alpina engine should produce 462 hp and 516 lb-ft of torque, and an eight-speed automatic and all-wheel drive should also be part of the package.

An Alpina D4 diesel engine may also be developed. Alpina offers a 3-Series-based D3 S diesel with 350 hp and 538 lb-ft of torque.

Other Alpina upgrades include a sport suspension, improved aerodynamics, and Alpina's signature multi-spoke wheels.

It's unclear if the B4 will come to the U.S., as BMW doesn't seem to have any plans to produce the M4 Gran Coupe we might see. Alpina models currently available in the U.S. include the B7 (7 Series), XB7 (X7), and B8 Gran Coupe (8 Series Gran Coupe).

We'll keep you posted on developments.