Hmm... this would imply that all head gaskets, when all else is equal, should fail at a similar rate. Even someone who drives more aggressively (but doesn't overheat) shouldn't fail significantly faster, but this doesn't seem to be the case.

john

> Yup, the gaskets harden with age and start to leak. They live a hard
> life, dealing with pressure, wide temperature swings, and expanding and
> contracting metal.