2008 Yukon XL 5.3L - Range Active Fuel Management Disable Device
Excellent device, highly recommended. Works as expected and keeps the vehicle in V8 mode. It really doesn't seem to impact fuel mileage. Note that you are supposed to remove the unit if you don't drive your vehicle daily since it will slowly drain the battery. GM has an issue with these engines running in V4 mode so this is a handy device to have. I replaced the driver's side valve cover as indicated in GM's technical service bulletin for the engine. I don't have an oil burning issue yet.
Great results EPA and performance!
So far I have put about a thousand miles on my 2000Yukon XL with the bullydog and fuel averages went from fifteen to eighteen combined with a noticeable difference in performance of throttle response. It seems like in time the Bullydog will pay for itself and make the truck more usable with both power and MPG increases. Auto anything did a great job on price and getting it here quickly once again. I would definatly recommend this product to anyone and suggest auto anything as he place to get it.