[Helter]

There's a new grout on the market, a type of epoxy grout which is suppose to be stain resisitant. I think Lowes or Home depot carrries it. I was planning on using a dark colored grout so stains shouldn't be a problem.

As far as using heavy duty equipment on porcelain tile, I don't know anyone doing that. I'm not sure how well it would be in shop conditions. I'm just parking my car there. I can't see road salts being a problem if you live in a cold region like I do. especially with a sealant applied.