For anyone thinking the BMW M division has become a little soft over the years, may we introduce the new 2016 BMW M4 GTS. The car is the production version of the M4 GTS concept car unveiled earlier this year and is the first of the M division’s special models to be confirmed for the United States. It arrives early next year, as a 2016 model.
In case you’ve forgotten, the M4 GTS is the successor to the M3 GTS launched in 2010 but never sold locally. It follows a successful formula utilized for previous BMW specials such as the M3 Evolution (1988), M3 Sport Evolution (1990), M3 GT (1995), M3 CSL (2003), and the aforementioned M3 GTS, and that’s an increase in power combined with a reduction in weight.
Power comes from the M4’s familiar turbocharged 3.0-liter straight-six, however, the engine has been upgraded with a new water injection system that not only boosts power but also improves efficiency. Peak output registers at 493 horsepower and 442 pound-feet of torque, which is up considerably on the stock model’s 425 hp and 406 lb-ft. Despite the performance increase, fuel economy is said to be largely unchanged. The standard transmission is a seven-speed dual-clutch unit.
So what will the M4 GTS do? BMW quotes a blistering 0-60 mph time of just 3.7 seconds. Top speed is a tick under 190 mph and a lap of the Nürburgring takes just 7:28.
The water injection system sprays water in both the intake manifold and directly into the cylinders, where it helps cool the pressurized mix of air and fuel prior to combustion. This cooling effect makes for more efficient combustion, leading to increases in both power and efficiency. In addition, the final compression temperature in the combustion chamber—and therefore the engine’s tendency for detonation (knock)—is reduced, allowing for more boost and earlier injection timing.
The system relies on an arrangement of three water injectors in the intake plenum chamber, where each supplies water to two of the engine’s six cylinders. A 1.3-gallon tank is located below the trunk and is joined by the water pump, sensors and valves. BMW concedes that under track conditions, this tank might have to be topped up with water every time the vehicle is refueled. However, under normal everyday operating conditions, the intervals are said to be much longer. Even in highway driving, the water tank only needs topping up at every fifth refueling interval. Systems are in place to ensure the engine is protected should the tank run dry.