Quote Originally Posted by fawk_you
I need this information for a court date that is coming up April 12th. They are trying to prove that the speed-o on my car was wrong due to the size of the rims or whatever compared to stock size. I cant get the information due to not having the car in my posession... I cant have it calibrated. Thanks ahead of time.
-----------------------------------------------------------------------

With a known radius, what is the forumula to compute the circumfrence of a circle.

Known radius, 15" and 19"
7.5 and 9.5


3.14xRxR right??? or what?
15" radius? 19 radiu? so a 30" wheel and a 38" wheel?

you want to go by size of your tire vs stock tire. you can have a 15" wheel with a 195/65R15 on it and have a 16" wheel with a 215/40R16 and they are .01 inches off depending on manufacturer. This is how it is with my stoc wheels vs new wheels.

You can also throw a 215/55R16 instead of the 215/40 and its going to give completely different numbers and a large difference in circumference.

just food for thought since your brining equations into it you might want to further think it, hate to see the court tell you your looking at the wrong aspect of it.