Simple newbie question

What does inch up mean?
Ex:Some models are under the subject inch up...

If the wheel is accurately scaled down in the same scale as the rest, the wheels look too small, because human eyes don't register objects in two sizes (real and model) the same way. So, in order to look better in miniature size, manufacturers have to deform the body and change measurements etc.
The most noticable is Tamiya, where the body is widened and flattened to make the model look better.
"Inch-up" is the term used by a Japanese manufacturer called Fujimi, and their wheel sizes are enlarged by 1 or even 2 inches.

Cool thanks

I didn't know that! Very interesting, indeed!
Thanks, Master Fukuda (your site is one of the first I found when I started searching model-related sites on web... and I'm a fan!), for this lesson!