[Loomis]

Anybody out there ever put 265R18's on a 99-04 Super Duty? I want to put some on mine, but am curious about clearance between the back of the tread and the inner fender, with the wheels turned to the locks. Looks pretty close with the 265R16's Ford put on there stock.

Also, has anyone tried "warming" the inner fender and re-shaping it for more clearance?

 

[Justaguy]

You can still have clearance running these size tires with different size wheels. The thing to start looking for is the aspect ratio of the tire. A typical tire size, for instance, on my '00 super duty is 265/75R16. Here the 75 is the aspect ratio of the tire. That means that the sidewall is 75% as tall as the tread is wide.

And now to answer your question, yes they will fit and easily so. What you have to do is run a lower aspect ratio tire, say 265/65R18. This way you have the 265 millimeter tread width, a larger wheel diameter, and a LOWER sidewall. Now your tires will clear your inner fenderwells without heating and reforming them, risking damaging sensitive electronics that have a tendancy to hang out on the other side of those fenderwells, pesky things anyways.