so having replaced my fuel pumps Im now seeing 29 MPG IN TOWN! Two fill ups with regular gas in sequence..both carefully filled. Went 295 on 10.2 I suspect I had low fuel pressure although there was nothing wrong with high speed performance.. 200,000K miles with fresh head rebuild, new water pump and..the tires could use more pressure Probably get 30 easily on highway which is just great..

The car would drop to 18 at times in town..I think it was the fuel pump issue..low pressure from one cuting out or from blockage in the check valves causing issues.

97 SL..about the water injection, Yes, as you say, and its been used as mileage boosting feature in various cars and for a temporary assist in aircraft takeoff during WWII due to the HP increase obtained, yes it will cool cylinders and also increases compression.. Way back in the Carter yrs there were fleets using water injection with very substantial mileage increases...Why its not standard has always baffled me..issues with corrosion or some other side effect I suspected, maybe it causes incomplete combustion and pollution increases..

Interesting points..!