I've been trying to just pin down a size here, and it's driving me crazy. In an unleveled F150, how large can I go safely? 31? 32? 33? It seems 35's should only be attempted with a leveled truck.

Is there some sort of a table out there that shows if I have a 33" tire, with a rim spacing of 4" (9" rim - 5" backspace) that it will clear? I don't need an exact number, but what will be close, and what will definitely be too big?

 

4x4 or 4x2?

 

4x2

For example, a 285/55/20 is 32.3", but a 275/55/20 is 31.9", and a 305/55/20 is 33.2".

In my case I am not shooting for a specific size. I just want to know what the max is, so I know where to stop looking.

 

I'd go with a narrow 33 inch tire, like the 285/55-20 unless you add a leveling kit. Then you can fit a wider 33 like a 305/55-20.

 

Thank you. Looks like I'm going to go a bit smaller to a 275/55R20.