I've been on this forum now for several months and one thing that I can't figure out is how, when talking about the overall height of the vehicle, some people will mention their rim size (i.e. 18" wheels instead of the factory 17" wheels), rather than their overall tire size (i.e. 33" tires, etc). I read a post not too long ago saying something like "My '13 F250 with factory height and 18" wheels fits just fine", or something along those lines. Can anyone explain to me why people quote their wheel size rather than the overall tire size?

On another note, I frequently see people talk about their tire size as "315s", or "275s". Again, without the rest of the numbers, those numbers don't mean much at all. Some "315" tires have a much smaller overall diameter than other sizes with much smaller first numbers.

Is this a case of people just not understanding what really makes the overall diameters of their tires? (and in turn, how that affects the height of their vehicle) Or am I missing something?

 

On the SD's, a lot of time we will refer to just the wheel size in discussions that involve the tire sizes. Using the standard factory common sizing: 20" would be the 34.1" tires, 17" would be the smallest 31.5" tires. The 18's is where there is no clear cut size; I feel most have the 33" 275/70 and less have the 275/65/18.
"My '13 F250 with factory height and 18" wheels fits just fine", . This could be referring to running larger tires on factory wheels and avoiding rubbing issues.
I get what your saying though, it makes it much easier if the poster gives all the pertinent info so we don't have to assume.