tire size affecting odometer?

94mx3precidia · Post by **94mx3precidia** » June 18th, 2007, 11:32 am

hey, would tire size affect the reading of the odometer? How does the odometer work? I know ive got bigger tires on my mx-3, i think there 205. So far it says ive driven roughly 140klm since i last reset the trip meter and it doesnt seem like ive traveled 140klm. I need some input on this situation, thanks.

babyblueMX3 · Post by **babyblueMX3** » June 18th, 2007, 12:20 pm

yes tire size affects the speedometer
the height will, not the width.
205 is the width of the tire in mm
what's the other number. 55 ? (that number is the percentage of the width in thickness, that's the number you are looking for)

94mx3precidia · Post by **94mx3precidia** » June 18th, 2007, 12:46 pm

im not sure what the numbers are, ill post them when i get home. How much would it affect the spedometer? enough to get pulled over? If the tire is bigger does it read that your going faster?

Thanks.

Post by **Mooneggs** » June 18th, 2007, 12:54 pm

somebody posted this a while back but this will answer all your questions if you know what your car came with stock...

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

94mx3precidia · Post by **94mx3precidia** » June 18th, 2007, 9:18 pm

ok so ive done some reasearch and i think the stock size is 205/55r-15. right now im using 185/65r-14. Using the calculations mooneggs posted i get a difference of 1 mph. so all in all its not that bad, i was a little worried that i was goin too fast through the 40 zones in subdivisions.

Post by **Mooneggs** » June 19th, 2007, 10:25 am

you are exactly right. I'm using 205/55/15 on my slow car and now I have 185/65/14 on the fast car...

I can't remember the last time I did 40...