In my 1980 4x4, I am running 33 x 10.5 x 15R BFG Mud Terrains with 4.37 diffs currently open / open. I like the way it drives in city, on and off highway. It's got a pretty healthy 20R and Marlin's 5spd L52HD and dual ultimates. I have never been spoiled with any power in my life so I feel it's adequate. On trips to and from Phoenix and the SF Bay Area it has a hard time with the hlls. It may be in my head but when I run 91 Octane in it on such trips I can actually get up into 5th gear and hold a good speed on the flats.