Alpina, which recently became a wholly-owned subsidiary of BMW, has just revealed the new B4 Gran Coupe, a fettled version of the regular 4 Series Gran Coupe and a theoretical equivalent to the M4 Gran Coupe BMW will never build. We previously caught a glimpse of the newcomer undergoing winter testing, but now it’s ready to tackle public roads and hunt down the competition.

The 3.0-liter inline-six now produces a potent 488 horsepower and 538 lb-ft of torque, allowing the tuned Bimmer to hit 62 mph in 3.7 seconds before topping out at 187 mph. A specially adapted eight-speed ZF automatic transmission sends the power to all four wheels. To put that into perspective, the B4 Gran Coupe is quicker than all M4 models, with the exception of the Competition xDrive.

The muscular performance comes courtesy of Alpina-specific flow-optimized turbine housings and a larger intercooler intake, along with a revised air intake duct. Even the cooling system has seen extensive updates, with Alpina fitting a high-performance cooling system comprised of a powerful main cooling package, among other things.

But this is an Alpina, not an M car, which means comfort is an equally important part of the equation. To that end, the German tuner has fitted upgraded bushings and mounts, along with unique dome-bulkhead reinforcement struts. Stopping power is provided by stupendously big brake discs, measuring 15.6 inches at the front with four-piston calipers and 13.6 inches at the rear.

Those planning on really exploring the dynamic capabilities of the B4 will be pleased to know a high-performance braking system, replete with drilled composite brake discs, is available at extra cost.