On the highway, I can hit 50+ if you stay in fifth. Busa drink more gas at lower rpms. Guys he has an 06, should be under warranty. He needs to go throw a fit at the stealership. All good points on how to correct, but at His first maintanence, they should have checked everything for him. I am surprised with no mods they started messing with his map. I would think an idle adjustment and checking his chain tension should have done the trick.