Pebble Beach: GTS treatment for BMW M4

BMW has hit the M4 with ground-breaking water-injection, OLED rear lights, lower fuel economy, a hike in power and even more speed.

To be shown for the first time alongside the wild 3.0 CSL concept at this weekend's Pebble Beach Concours d’Elegance in California, the Concept M4 GTS is the upcoming limited-production M4 GTS in all but name.

The road legal coupe will be the successor to the 2010 M3 GTS, with more power from its water-injection system, though BMW is refusing to admit just how much more power and torque it will have.

It will use a multi-point injection system in the inlet manifold to spray a fine mist of water in to the cylinder to cool it. The water evaporates before the combustion cycle begins, reducing the risk of “knocking” and giving M the chance to increase the turbo boost safely.

While BMW is coy about the Concept M4 GTS power figures, a 1 Series water-injection prototype we tested a month ago saw its power rise from 150kW to 160kW and its torque up from 280Nm to 320Nm.

Critically, the compression ratio rose from 9.8:1 to 11:1, though that was with the direct water-injection system that was a generation more advanced than the Concept M4 GTS’s indirect system.

But if the Concept M4 GTS carries over a similar increase in power, it would pick up more than 20kW and an extra 80Nm of torque, which should see it slip beneath the four-second barrier to 100km/h.

That will make the GTS the new range-topper of BMW's existing M4 sports coupe range, pricing for which was slashed by more than $16,000 (to $149,900 plus ORCs) two weeks ago.

“While the M4 Coupe embodies the ideal combination of motorsport genes and unrestricted everyday usability, the BMW Concept M4 GTS previews an emotionally powerful and exclusive special model conceived with an eye for trailblazing technology and a keen focus on the racetrack,” M President Frank van Meel said.

“Despite its outstanding track ability, it is still fully road legal. This is racing technology for the road in the truest sense,” he argued.

The technology has been in development for a long time at BMW (the powertrain has been tested in the MotoGP Safety Car all season) and is expected to find its way into all of its higher-boost turbocharged motors.

That’s not all, though, because the track-focused nature of the Concept M4 GTS means it makes the standard M4 seem almost genteel. Both the carbon-fibre front splitter and the carbon rear wing are manually adjustable so the car can be tuned to different tracks and the bonnet is also made from carbon-fibre reinforced plastic (CFRP) to reduce weight and lower the centre of gravity.

The front wheels are 9.5J x 19 and 10/5J x 20 forged alloys, while Michelin Sport Cup 2 rubber (265/19 front and 285/30 rear) wraps around them.

But water-injection isn’t the only technology arriving with the Concept M4 GTS. Just as it trumped Audi in the race to Laser Lights with the i8, it’s also planning to get Organic Light-Emitting Diodes (OLED) onto market first, too.

Instead of being a single-point light source, like an LED, OLEDs light up their full surface and are flat, at just 1.4mm fully installed in the Concept M4 GTS.

Far from the first GTS in M history, BMW insists the Concept M4 GTS can trace its history back through the M3 CRT in 2011 to the M3 GTS in 2010 to the M3 CSL in 2003, then via the M3 GT in 1995, the M3 Sport Evolution in 1990 all the way back to the M3 Evolution in 1988.