Rowhard has those Toyos in 285/60-18.
Here's a tire size calculator that's really handy when you're comparing different sizes to see how they'll fit compared to stock etc....
Comparing those two sizes, looks like the 275 is 32.1" vs the 285 is 31.5 and is also a little narrower. http://www.rimsntires.com/specs.jsp
Wow, those look good on the VX. I think I'm gonna get those for the VX and I'm gonna end up getting Nitto Terra's on the H3.