I am running the Toyo MT 37x13.5x17 with 4.88 6 speed manual with an Atlas 4 T-case w/ 2x. I have the G2 Core D44 front & D60 Rear 5.5" Rubi extreme long arm. I love the setup and still get 14 - 16 mpg. But I tow an overland trailer so I am not concern about the weight of an RTT plus roof rack...