Originally Posted by EPOS
Why not just do propane? I have no clue but thinking that's easier and more gains.
Lots of info on that out there to compare propane vs Nitrous vs H2O/methanol. Tend to not be convinced propane is a good option, but have no direct experience with it.
Aspects I like about the water injection are the cleaning properties and EGT/particulate reduction. Direct injected, EGR equiped engines can get carbon build up in the intakes very easily and the water injection helps keep things clean, as well as reduce peak cylinder pressures when extra fuel is being added. Direct measurements with the BT tool show good EGT reductions on the D.