I am sure this has been asked before, but I have searched the archies and came up empty handed. What is the biggest tire that can be used on the stock rims of a 2003 SD 5.4. I believe my rims are 16X7. Just lloking to get the most out of the rims. Short on cash so new rims are not possble at this time. Thanx, Bill

 

The widest RECOMMENDED tire width is 265mm (about 10.50 inches). Any wider than that and the tire starts to bow and wear down the center at rated pressure. Again, that's the recommended from the tire manufacturers. Plenty of people have gone larger (I've heard of 315mm on a 7" wide rim), but I wouldn't recommend it. Safety, along with tire wear, I would think becomes an issue then. I have 265's on mine right now. I'm going to go to 285's soon and will be getting an 8" wide rim for them (although most people put 285's on their stock rims, I'm just OCD that way).

Just my .02

 

I've got a set of 285/75/17's coming in tomorrow (~34x11) that will be running on my stock 17x7.5" rims. I don't anticipate any problems. It'd probably be too narrow for running on a 20" rim, though. Of course if I were buying new rims I'd go ahead and go a little wider, 8" preferably or 9" max. No need to go really wide.

 

You should be fine. Most tire companies recommend 7.5"-9" wide rim for a 285 tire.