When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
i would do same size front and rear so that you can rotate them.
if you do 18's in the rear, run them in the front too.
run same width front/rear too.
might as well maximize the life of those expensive tires!
i mhave 18s all arond with no issues. I used the "MIATA" calculater ( seen in earlier post) to determine the tire hieght. Notice that on that calculater, it also TELLS you what your speed difference is.
great little tool.
by the way.. I went from 17x285x40 to a 18x295x35 and the tire hieght is virtually the same.