I want to continue to use my stock 18 inch polished rims but I want to get a better, more aggresive tire that is a little larger (about 1 inch). I have a teraflex leveling kit to throw on but I want to get the tires ordered now. I found this awesome calculator that even tells you how far off your speedo will be. http://www.miata.net/garage/tirecalc.html
I was looking at maybe 265/70 R18 instead of the stock 255/70 R18. What is the best size that won't blow off my rim if I air down for the beach?