Originally Posted by
rangcrx
but if your motor does not have the higher compression to act with the higher energy then its usless..i did this little test my self on a trip to miami i got 31 Mpg on 87 then on the way back full with 93"and seemed to run alill rougher"got 27 mpg fully stock d16z6 automatic
Depends if the vehicle is requiring "premium fuel only". A lot of turbo cars have lower compression and run 93+ simply because of many reasons but one big one being knock.
The only way to do a true test is by calculating it at the same average speed and same distance. A trip from here to Miami varies coming and going being that depends on the traffic, how many times you let off the gas pedal and for what distance were you doing a different speed. Also depends on where exactly you got gas at... some gas companies add/take away some additives versus others. This will hinder performance and mileage as well.