Good morning,

I am looking for an old link that I forgot to bookmark. I have tried searching without any success. It was a link to a tire calculator that you provide different sizes and it would indicate the difference in speedo accuracy, as well as other items. You could compare several sizes at the same time.

If anyone has this bookmarked could you respond with the link.

Thanks,

 

This the one you are looking for?

http://www.discounttire.com/dtcs/infoTireMath.dos

 

I really like this one too

http://www.1010tires.com/TireSizeCalculator.asp

 

Thanks for the links, I have now bookmarked them.

 

This one is good as well.

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

 

Here are 2 websites both providing a tire calculator. They don't agree when comparing. One has the speed more than the original size and the other has it less.

Check out both sites and put in some numbers. Use the same numbers and compare your results.

I don't know which one to believe.

Thanks,

 

Actually, they all agree. It is just the way each site presents the results. In all cases the speedometer reads too low.

 

Here, try 235x75x17 and 245X75X17

 

Discount
Your speedometer reads 65 real speed is 66.24

1010

real speed 60 speedometer reads 58.8

Miata

speedometer reads 60 real speed 61.1

In all cases speedometer is low compared to real speed.