Does any one know what the biggest tire I can put on my 2012 F-350 diesel? I want to get a four 20x9 D529 +1mm and want a tire that looks good and rides good and don't look smell on the truck. I do not have a lift kit or anything on it. I'm assuming someone know much more then I do. Any help would be greatly appreciated.

 

Here's a picture of a set of 285/75R18 on stock wheels

 

Thanks for the reply, but I have 20" tires.