Just bought the 98 Base Prelude 2 weeks ago. It requires premium gas but the manual says you can use regular. I filled it up with regular when I first got it because I did not know it used premium. I got a liitle over 28 mpg (70% hwy, 30% city) with regular. I filled up with premium (93 octane) this time and will post what kind of mileage I get with it. The car is getting better than the EPA average but I dont get down on throttle a lot. Going to change the spark plugs after I check the mileage with premium and see if that increases the gas mileage any.