SuperBuickGuy
Well-known member
I added a tire diameter calculator to the page. Remember that this is just for estimating.. it's in the ball park, though.
Once again.. This calculator doesn't have a damned thing to do with the inaccuracies of the factory gauges. It calculates speed by considering engine RPM, tire rpm, and tire circumference. I realize that tires are not perfect circles and there are many variables to take into account like vehicle weight, inflation, growth, etc.... but your typical consumer tire likely doesn't grow 2 inches unless you've hit warp drive and are moving into a new galaxy. The miniscule growth is not going to skew the numbers enough to invalidate the numbers.
I just did some checking on bias ply min growth slicks for drag racing. Hoosiers will grow about 1.5" at 60 degrees F and 3" at 100 degrees and 5" at 100 degrees and 180 mph. A typical passenger tire isn't going to see anything near that.
And this gearing calculator is digital. What if it lies to you?
numbers lie.... don't believe me - they even have a term that means lying with numbers....
it's called "statistics"