Update on Dirt Commanders: as soon as I put them on I could feel a vibration start at about 25mph and get worse at 30mph. I would of swore it was an engine vibration not a tire vibration. Low and behold I put stock tires back on, just to check, and vibration went away. One other thing on Commanders: rear end of Ace would slide out a little on curves. Thank God for Costco return policy! I returned them yesterday.