Okay 15 years ago when i was less wise... i told a few budies that i could get my car to 95. they didnt belive me so we took off down a baren west texas road. that was straight for about 5 miles and took off. we got it to 95 and they said it was afluke and that i had a tale wind. so we did it the other direction. so using the RPM calculator based on tire size and gearing i had to be turning about 4500 rpm. and the engine is still running to this day. I know now that my speedo is about 10% off, but those guys never need to know that. 85 is good enough. its amazing a rabbit didnt jump out , or tire blow out , or something failed and we get killed.