You Sure? Im getting 21 to 24 MPG Average. On Reg. Im getting 16 to 19 Average. Im pretty sure its helping. But you may also be right, maybe the Mid Grade itself it just doing it just fine, and Im wasting money. Ill run a couple of tanks to see. Im letting the Trooper sit for a bit so I can gap the plugs and see if it helps any. Its running awsome though.( these little 2.6's run really really well- before it was running on 3 due to a burnt exhaust Valve on #3 Cyl.) Had to pull a car out this morning due to them sliding into a ditch after screwing around. Low Range Baby!