Postby Rudman » August 15th, 2007, 11:27 am
^^Say, for instance, that with the 18" rim he has to run 215 35 R18 tyre with it. The stock size for these lancers is usually 195 55 R15, therefore, the 18" rim and tyre package will be +2% oversized from stock.
This may no seem like much, but if his indicated (speedometer) speed is 165kph, actually speed is closer to 170kph.
With a bigger rim and tyre, you are actually traveling faster than what is indicated. The reading on the spedometer is calibrated to the RPM of the stock sized wheel. This is why U try as best as possible not to deviate from stock rolling diameter when upsizing the wheels and tyres.