What is water injection?

According to Bosch, even the most efficient combustion engine can waste up to one fifth of its fuel. As an engine overheats, gasoline is used to not only power the engine but also cool it. It is this type of waste and inefficiency that is spelling the end of the combustion engine.

Bosch believes, however, that they have found a breakthrough solution that not only improves efficiency, but also improves performance. The solution is called water injection, or if you work at Bosch, "WaterBoost".

Water injection is based on the fundamental principle that an engine cannot be allowed to overheat. Therefore, before fuel is ignited in the engine, a small water injection valve which is connected to the car's water pump sprays a fine mist into the car's intake manifold to lower temperatures. This reduces internal knocking and increases ignition times.

Bosch says that in doing so they have been able to increase efficiency during high acceleration and long stretches of freeway driving by up to 13 per cent, reduce CO2 emissions by four per cent and, in the case of turbocharged engines, increase performance by five per cent without changing the amount of boost pressure or the displacement of the engine.

"With our water injection, we show that the combustion engine still has some tricks up its sleeve," says Dr. Rolf Bulander, chairman of Bosch Mobility Solutions.

This type of technology is ground-breaking, but only one car employing the concept is in mainstream production so far, the upcoming and very rapid BMW M4 GTS.

This is mainly because the WaterBoost technology has been co-developed between Bosch and BMW.

In an article first written by British publication Autocar, BMW disclosed it is now already suggesting that more of its models could employ the use of water injection from 2019.