Originally Posted by kotik
Tire size is 285/30-19.
Hmm... maybe i had a bad calculator before.... My math is bad this morning... so what is the descrepancy % if shown speed is 337km/h?. About 7%?
With this tire size, theoretical max in 6th at 8400RPM is 309km/h. This means about a 9% error.
These are all approximations though. The actual tire diameter is not necessarily a direct correlation to the "quoted" size and aspect ratio. Further, especially at these high speeds, tire slip is not negligible which induces an even greater error. The easiest way to figure out the exact speed is with a GPS.