"Installed a GForce chip in my 2007 Nissan 350Z. According to the trip computer, my highway mileage went from 26.3 to 28.6 (+8.7%) and local mileage from 18.9 to 19.5 (+3.2%). This took 100-200 miles of driving. Reminder for those that may be a little ignorant, that you need to compare mileage on similar routes at similar speeds, similar weather (cold air brings your mileage down, and so does driving into a wind). As to the HP and torque, I don't have a dyno, but I can now do 0-60 in 5.0 seconds. I liked it enough that I then put one in my wife's PT Cruiser. Not only has the gas mileage improved about the same %'s, but it is easier to notice the added HP, since the Chrysler 2.4L is such a dog. Send an e-mail to their tech dept to make sure you hook into the correct two wires!!"