yeh so my bro jus put 2002 si rims on his car and we were comparingn them to his stock wheels and the tire height for the SI rims are higher or seeem to be...the tires seeem to be bigger heightwise or watever...my friend was sayin that this would mess up the odometer/speedomter...he said we might need to re calibrate the wheels...is this neccesary and does this really affect the car alot..please help..thanks..he also said that the steering wheel feels heavier...and the tire sizes are....

stock 185/65-14

Si rims 195/60-15

 

If the overall diameter of the wheel + tire is greater than that of the stock setup then the odometer will read slower than it should. If it is less than that of stock it will read faster than it should. By changing the height of the tire to match the stock wheel + tire it will be corret.

 

so with teh specs i provided is mine higher or lower...and thers no way hes gettin new tires..jus spent money on that package lol...lemme kno

 

stock was about 23.6 inches in diameter

Si's are about 24.2 inches in diameter

There's your answer.

 

^ Josh is Teh man. hows the ferio.?

 

With that rim combo, your speedometer (and odometer) will read 3.2% too slow, at 60mph indicated you will actually be going 61.9mph.

If you can get something in 195/55R15, that would be ideal, even though it's still kinda narrow.

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

It all depends how far off you don't mind being. Right now I am running 215/55R16's on a car designed for 205/60R15's. In other words, my speedo/odo is 2.5% too slow.

 

You just had to one up me didn't you? :fawk:

 

Wow, if I do say so my self that was a pretty impressive explanation. Cool tire calculator Kai, thatll come into use pretty soon.

 

wait if it reads slower then why would i be goin faster at 60mph....and also does that mean it will put more miles on the car or less...i'm so confused

 

well yeah you would put more miles on the car, but not the car itself just the odometer.