When I had my Willys wagon, I had 33" swampers on it. I ran them at 25 psi on the road, anything more and it was a real stiff wide. I dropped them to 8 when wheeling, if I forgot to drop them, it sure was noticeable. I would run them home from wheeling sometimes at 8 since I didn't have an onboard compressor. If my friend was with me that had a compressor on his jeep, and we had time, I'd air them back up.