Do the math. 7th grade. Speedo is off proportional to tire diameter difference.

 

Just calculated. Your 245X45X16 are 24.7" diamneter. Your 225X55X16 are 25.7".

1" divided by 25.7" is a 3.9% difference. So your speedo will read 3.9% faster than before. BTW if it was reading a couple percent fast with stock size, this adds to that error.

 

BTW you sure about that 245X45X16 size?

 

YEP.. they are Kumho Ecsta 712 in 245/45/ZR16

So I am actually going slower than the speed that the speedo is reading IF the speedo was correct with stock sized tires..

bad picture I know.. but I finally found a size that I like.. I've had 225 50 (too narrow) and 255 50 (too fat and tall)

It just needs to be lowered now..

 

An easy way I use is to check mileage between mile markers on the freeway. If you read 9ths instead of a mile then you know your reading 90%. therefore you need to change you speedo gear by 90%. I like to do it over a 10 mile strech to cut down on chance for error.

 

An easy way I use is to check mileage between mile markers on the freeway. If you read 9ths instead of a mile then you know your reading 90%. therefore you need to change you speedo gear by 90%. I like to do it over a 10 mile strech to cut down on chance for error.

Even easier....use the Tire Size Calculator



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Even easier....use the Tire Size Calculator

THAT IS EXACTLY WHAT I WAS TRYING TO FIND....

THANKS..

 

THAT IS EXACTLY WHAT I WAS TRYING TO FIND....

THANKS..

:salute:




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