I suppose tire life depends on the tire itself. When in doubt, check with your LBS?

I do road riding and some dirt/gravel trail stuff. A lot of commuting and utility riding. I have Vittoria Randonneurs on both my bikes. (with reflective sidewalls, as it is often gloomy here in Seattle and I need all the help I can get to be seen) Magpie-like tendencies rule my brain: show me something shiney and I *will* ride over it. "Broken glass!?!?! OOh, boy, ride over it!" "Twisted chunk of metal!?!?! MINE, let's ride on it!" "Nail heads sticking out of a wooden bridge?!?! SCORE!!!!"

So far neither set of Vittorias has suffered from a puncture. (Knock wood) One bike has 28mm, the other has 32 mm.

I don't remember who here on TE recommended them to me (Veronica? Jobob?) but I am very grateful!

PS: you can buy a chain gauge or just have your LBS run a quick check with their chain gauge. It'll tell you quickly if your chain is worn.