how can i tell how much the speedo is going to be off?

[EstoMax]

my brother has a 97 jeep wrangler sport 4.0 and he got some 33's put on.. now i realize that the speedo is going to be off, but does anyone know by how much? can i just calculate the diameter of stock and the new 33's and then find the percentage difference? would that be the amount that the speedo is off by?

thanks.

Max

[ryder_23]

http://www.miata.net/garage/tirecalc.html

if you know the size it was before, from stock, u can find out new size

[EstoMax]

awesome tnx bro

max