Spy-Shots of Cars

This BMW M4 has a sticker on the side that says Safety Car, Official Car of MotoGP, but we're not sure if that's what it is. In fact, our spy photographers are convinced that this is a mule for an upcoming BMW M4 GTS. After all, the previous generation M3 had a GTS - remember that striking orange coupe with the more powerful 4.4 litre engine? It raised power to 450 horses, up from the standard 4.0 litre's 414 horses.

BMW has only just unveiled their MotoGP safety car about a week ago. Not just an M4 equipped with fancy livery, the car also featured a technical update - a water injection system which helps boost the car's performance.

Water is injected into the intake as a fine spray, cooling the exhaust air during vaporisation. This lowers the discharge temperature in the combustion chamber and thus reduces the tendency for knocking, allowing the engine to have higher charging pressure and an earlier ignition point.

Improved performance can be achieved without increasing the heat applied to performance-related components, meaning that reliability is not affected. How much exactly? BMW didn't say, but this is one way to get more power out of a turbocharged engine.

On track, the water tank has to be replenished whenever the car refuels. During more normal operation, the intervals between water refills are considerably longer, roughly once every five refuelling stops. To ensure the system is as suitable as possible for daily use, it does not require any additional maintenance, BMW says.

The thing is, BMW says the water injection system is not just a fun project for the engineers, it is going into a production M car soon. Thus we wonder if the MotoGP safety car stickers are the only thing this mule has in common with the actual safety car - will an M4 GTS get a water injection system fitted as standard?