hi, changing gears does affect E.T. and 60' times. went from 5.13 & 29.5 tire to 5.57 & 30" tire, E.T. dropped .30 & gained 1 MPH. 60', dropped .13. car was faster period!!! also, rpm was 6400 after is 7000 rpm +. it doesn't lay down last 300 ft either.