AHA, now this opens up a discussion about the appropriate tire pressure for passenger car tires. Which number is correct? The number on the tire or the number on the door jamb?

I say that the number on the tire is a Max Pressure number and isn't useful for your normal running pressure. On the other hand, how can the number on the door jamb be right when you buy a different brand of tire?

Here's what I've experienced, though:

- If I fill it up to the number on the side of the tire, that's TOO MUCH. The tires wear out more quickly, with the wear pattern being in a line down the center of the tread, and the edges of the tread not wearing hardly at all. This tells me that the tires are "bowed outward" at the center and thus are overinflated.

- If I fill it up to what's on the door jamb, that's TOO LITTLE. The tires seem like they have mushy squish on the sidewalls where they meet the road, and the wear pattern is that the edges of the tread wears out more quickly than the center of the tread. This tells me that the tires are "bowed inward" at the center of the tread and are thus underinflated.

So I go with a number that's somwhere above the door jamb number. I think my door jamb number is 30, and I try to hit 33-35. Higher if I'm traveling with a heavy luggage load.

I'm sure CarTalk has answered this question a million times by now, but I don't know what their answer is.