Map & Hours Toll Free: (888) 882-8473 Phone: (905) 882-TIRE Fax: (905) 882-7422 Tire Calculator and Comparator Use the calculator to see what happens to your speedometer reading when you change the size of your tires and wheels. The graphic shows your stock tire selection in an outline overlayed on your new tire selection. Tire Calculator and Comparator courtesy of Eunos Communications LLC and Miata.net