37x14x18 Nitto tires on an H2

[Jim M]

I saw an H2 at the dealer that featured 365/60 R18 Nitto TerraGrappler tires on Boyd Coddington 18x10 polished rims. The dealer wanted $5000 for the upgrade and I almost passed out. I've been doing the research and found both the rims and tires for a little less than half that. But the tire/wheel combo was so tight! ("tight" means good to all you old folks). Using a tire metric conversion calculator I found that those tires were 37x14.5x18.

Here's my question: I like to off-road. No real rock-crawling. Mostly sand, dirt and snow in So Cal. #1 Do you think that these wider tires would rub when off-roading. I've read some posts about ordering wheels with a specific offset, but I'm clueless there. #2 Do you think there's any difference off-roading with 18" rims vs. 17" rims assuming 37" tires?

If I get them, I will definately post pics, before and after. The dealer pointed me to www.SMAHummer.com where you can see the wheels and tires but they only sell to Hummer dealers.