Such a system was installed on one of the latest models. As it turned out, the decrease in the fuel ignition temperature due to water injection gives a fuel saving of 8%, which is a consequence of the increase in the compression ratio in the cylinders to 11: 1 instead of the previous 9.5: 1.
Water for the water injection system is in a small tank. Getting into the intake manifold, it is sprayed into the smallest spray and reduces the temperature in the cylinders by about 25 degrees. The cooling effect also contributes to reducing the load on the pistons, valves and other engine components, increasing their service life.
The company BMW promised that after the necessary tests, the water injection system will be equipped with many serial models.