Hey George .....

Interesting that you are using the same width tires on your cars as I am .. however mine are 14" .... according to the Miata tire size calculator, the difference in the circumference between the 165-15 original tires and the current P205/75R14 works out to about 2 revolutions different per mile travelled... don't ask me in which tire's favor LOL ... my speedometer and odometer are right on for all intents and purposes. Now the only problem is that I can't seem to wear these particular tires out .... I took them off my late lamented 1982 S15 GMC several years ago the rears have that weird "computer designed" snow tread and even with them being a softer compound they just keep on going .... I had thought that they might not pass our safety inspection this year ... but they did ... however they are just about useless as a snow tire these days ... think I'll break down and replace them with a couple of all weather radials this summer before I head to Ontario for the CVC meet.

"Old VOLVOS never die .... they just become VERY COOL"
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Brett Sutherland & the 1.5 million mile 122 Canadian