I used a G Force chip once - (continue reading when you stop laughing) - ok - so I used it on a 2007 Hyundai Santa Fe 3.3 AWD - I felt the difference but have no dyno to prove there was an improvement. The downside? Could be unrelated - but I started getting codes for cat and o2 sensors maybe a year after I installed it. I agree that most cars have more performance to offer but limits are placed to preserve longevity and maintain warranty concerns.

 

That was my hope when I got my X-Type... seeing txfr cases go quite often on these I was glad to only have a 2.5 as I suspect the 3.0 is pushing the txfr case towards it's limits - let alone trying to up the power.. four wheel drive is designed for smooth pullaway and grip rather than trying to beat the boy racer in the Ford Fiesta beside you with the big noisy exhaust at the lights (but be assured by the next lights I *will* be past him nonetheless - with a very unhappy wife in my passenger seat :-) )