They mention the trapspeed thing in the owners manual. The reason it's higher is that the G-Tech gives your speed at the end of the 1/4 mile, while at the track, your trapspeed is your average speed over the last 60 feet of the track. So you should expect the G-Tech to give 3-5 mph faster than the track.AzN STi IMPREZA said:i have g-tech. it is somewhat accurate with the quartermile times. but when it comes to trapseed, it is pretty off. by like 5 mph. my bro ran 15.33 at 99.9mph. with injen cai in his 97 240sx. now that, is off.