MX-3.com

just wondering ourspeedo is set for our 15" rims, but i'm running 17's. how much faster/slower will i be going in comparison to what my speedo is showing me?

It doesn't matter what size wheel you have, it's what size tire you have.

What matters is the effective radius of the cover. If the new ones are larger, your actual speed will be greater than indicated, and vice versa. Multiply the indicated speed by the new diameter, and divide by the old to get true speed. For better accuracy, use the heights of the centre of the axle above the road surface instead of the diameters, but you'd have to put the old wheels back on to measure

<small>[ August 05, 2004, 05:56 PM: Message edited by: IanL ]</small>

Check out this link!!!! This will answer your question. Just put in your original tire size & then put in the size of tires your running now & it will tell you how far off your speedometer is.

Tire Calculator

that tire calc is great! unfortunately i'm running sloer that i thought...need to get 1 tire size larger to be just a little faster. anyway thanks again.