[CarlG]

In the mid 50's my dad always ran Sears tires that had a "time" warranty rather than a mileage warranty. Since he was putting a ton of miles on his car, and a lot of it was in the Arizona mountiains, Sears got to replace a lot of tires for him. Not long after that, Sears changed their warranty to miles.

As to the wear on Model A tires, a very slight mis-alignment will wipe out a pair of tires in no time at all. Don't ask me how I know that!