I`ve ran the biggest tires I can fit in the car on about every hotrod I built. Widest was 16x32 1/2" slicks, the narrowest are the 295 65 15 d.r. on my 68 fastback. I do street drive it some, it burns so much gas I don`t drive it every day. I have a couple of times ran a little smaller rims than was recommended, and ran the tires w/ a lower air pressure to make up for it. Running 22 lbs. on the 295`s now , on the 8" rims to get the tread flat on the ground, Seems to be ok, but all my cars have either been drag cars or street n strip type cars. Not interested in any roundy round stuff, as I grew up doing that on the street , too much traffic now to even think about what we used to do. TOO OLD TO !!