Originally Posted by Chris L.
Well, 93 is a good number, but if they get that number by adding ETOH.(ETOH has a high octane#)...then the # of miles/gallon will suffer because ETOH only has about 65% as much energy in it as pure gas....even though it has a high octane rating. If the station is on the Mo. side of the state line, then I'm almost certain it has ETOH in it...something like a 10% blend. There is
no more energy in a gallon of 93 octane pure gas than there is in a gallon of 87 octane pure gas...it's just a measure of it's resistance to "knock" (i.e., explode on it's own)...
So, a gallon of 10% ETOH 93 octane fuel will only have 96.5% as much "energy" as a gallon of pure gas (even if it's an 87 octane fuel).
I work in Mo. (Lukes on the Plaza), but live in Ks. ....way out by the NASCAR track....& usually wash them in the driveway.
Alright thanks for explaining the "ETOH" additive. I aswell always washed the car in the drive way at home but know I have to get accustomed to apartment living.