Originally Posted by Sea Doom

To add to Funf's data, here's how we've been doing, with a car (truck) generally half full of sports equipment, and standard RFTs and rims. The better tankfulls are Interstate driving, albeit above the posted limits. Not sure about winter/summer blends these data - some of it from a road trip to Kansas and Louisiana December/January and therefore winter blend? Something's not kosher with the OP mileage issues and self claimed throttle behavior!