What's the difference in trimming if I have 18" rims or 17"?

[knightsfs4]

I have the 18" rims. I was wondering what the difference was between rim size if I bought the same tire.

Jack

 

[ARK_SWAMP_RIDER]

You'll need to go up in height by five in order for the tire size to remain the same.
I.e. 265/65/18 is the same size as a 265/70/17.
If you stick with the same actual size, no extra trimming.

 

[knightsfs4]

So really 285/70/17 is 285/75/18?

 

[ARK_SWAMP_RIDER]

Nope, that's backwards. A 285/70/17 is the same size (relatively, might be off by a tenth or two) as a 285/65/18. For each size the rim goes up, the aspect ratio decreases.

This site is a great tool for figuring out different sizes, very helpful.

 

[knightsfs4]

That's awesome! i never knew that. thanks!