Originally Posted by Joreto

That's a big misconception coming from a video on youtube done by guys who apparently have no idea how to use the g-tech. I've tested my gtech on a drapstrip in a couple of cars and the most it's been off is by 0.1 most times where in 0.01 - 0.02 ....

Also other videos ...
http://www.youtube.com/watch?v=2Tyozgkc7dE&feature=related

http://www.youtube.com/watch?v=mmfwg5eoAFs