Welcome to the Turbo! Saab tire size calculator!
Thanks to our friends at Miata.net, We've secured this customized tire size calculator for you to compare your current tire size to a new and different size tire, or any two tire sizes you might think of (well, within reason).
Please note that this requires a Java-enabled Browser
For those still running TRX rubber (you can still get TRX rubber?), here's the comparitive data for the size Saab used:
180/65 390
Sidewall: 4.6063 in 117 mm
Radius: 12.2835 312
Diameter: 24.5669 624
Circumference: 77.1791 1960.35
Rev per...: mi 820.95 km 510.113
Once again, thanks to Gary Fischman for the Java Applet, and customizing it for Turbo! Thanks also to Miata.net where I found Gary's calculator.