What is proven is the gain in power thanks to water cooling (logic). Moreover it is announced in the title "the combustion cooled by water on an Audi TTS"
At equal power the engine may be reduced in weight and volume, or probable gain in consumption, provided that only a reasonable quantity of water
It is in the air of time, manufactured products are increasingly lightened in raw material.
When it comes to mechanics, you always have a very selective reading ... The cited article concludes with: "
FEV explains that the water injection can optionally be optimized to promote performance, we then get more 10% power, and more 18% torque, Or set to reduce power consumption. The fuel mass can then be reduced to 10%. Interested manufacturers to inquire from FEV.
At equal power, The engine can be reduced in weight and volume, Or probable gain of consumption, provided that only a reasonable amount of water
When it comes to F1 this kind of optimization is topical, on a production car it is only a bad commercial argument galore especially when you have much much more power than necessary to respect the regulations of speed of the highway code (and in addition that no one uses). The gain in consumption is not "probable" but real. The quantity of water consumed (weight) remains very reasonable (at least on the BMW) especially on this kind of tank (1693 kg).