I now run royal purple in the rear axle and in the motor and just doing that has added smoothness, MPG and performance, even lower RPMs. I need to run additives and see what happens. My Expedition is on a boat right now on its way to NJ to be picked here in a few weeks and I will have to try that since I have 7 hour drive to Fort Drum right off of the boat! My Ranger is being driven by my sister in law and she don't pay too much attention to the truck until a light comes on, then checks things, typical woman. Drive it till it breaks instead of doing preventive measures. The 6 P's- Prior Planning Prevents Piss Poor Performance!!!!