Tires - Do Priuses wear less than a conventional car?

Usually a new tire will have 10/32" to 12/32" of tread depth, depending upon the tire type. The lower end of that range corresponds to your 8 mm measurement.

 

Recall I read somewhere that in order to reduce rolling resistance Pri's tires are neither cambered or toed. Might get better tire mileage that way.

 

I was discussing the tire issue with a service manager where I bought my Prius....... He didn't know I owned one at the time. He said that Prius's were known for wearing out tires quickly. He didn't know it would come back to bite him when I showed up with printouts from Priuschat about people getting Toyota to replace worn out tires on car with less than 30k. Mine were shot @ 26k with no good reason...... Long story short, Toyota replaced mine free of charge as a "good will gesture" although they didn't admit to any problem as the manager did. But I got satisfied.