Originally Posted by NeverEnough
Well, that is true, but my own personal experiences have proven otherwise on two applications. I had an Upsolute Chip on a 1.8T MIV Golf, and Diablo Chip on a Focus SVT that dropped the fuel economy about 10-20%. I'd like to see that cliam be accurate for once.
Chips and power programs on NA vehicles usually do result in lower fuel mileage, but when done on supercharged and turbo charged engine usually result in the same or better fuel mileage if driven easy. In reality most people modify and driver harder resulting in less fuel mileage. My Duramax is 360/650 from the factory. It is reprogramed with EFI live and runs 500/900. If I drive normally to conservatively I get about two more miles to the gallon over stock.