Special-Edition M4 Bimmer Breaks Cover

BMW AG took the wraps off its M4 GTS concept car last night at the Pebble Beach Concours d'Elegance in California. A production version of the vehicle is expected to be shown within the next few months possibly at the Los Angeles auto show in November.

Described as a showcase for a performance-enhancing systems, the M4 GTS coupe features a host of advanced technologies.

The concept car is powered by a water-injected version of the stock M4's twin-turbocharged 3.0-liter inline-six engine. The system injects water vapor into the intake manifold to cool the air entering the engine and boost fuel efficiency and power.

The water-injection system reduces engine knock, which allows for the use of higher boost pressure with earlier injection timing. Performance numbers for the concept car's engine weren't released, but media reports suggest an 8% to 10% improvement over the 3.0-liter twin-turbo's 425-hp output.

To enhance engine cooling, the M4 GTS gets two more radiators, a revised intercooler and a separate electric water pump for the turbochargers.

The concept car also sports organic light-emitting diode taillamps, a track-ready suspension, manually adjustable front spoiler and a large rear wing. A carbon fiber-reinforced hood reduces weight and lowers the car's center of gravity, according to the carmaker.