[via Popular Mechanics]

5.) They're Damaged
So... you're telling us damage is bad? Wow. Guess we'll have to stop carving "Jalopnik was here" with a knife into people's tires and calling it a PR stunt. Actually, a careful inspection for missing chunks of rubber, bulges (unsightly or otherwise) and evidence of curb or debris damage can keep you from having to call a tow truck when you're miles from home.

4.) They're Deteriorated
Not to be confused with damage, deterioration happens over time due to atmospheric conditions — mainly ozone in the air acting on the rubber to produce dry rot. Deterioration can be sneaky, resulting in weak spots that can lead to a blowout. Look for spiderweb cracks in the sidewall and a dull, dusty appearance to the rubber.

3.) They're Overinflated
Contrary to what your friend Jeff told you, inflating your tires well beyond the suggested pressure will not increase your fuel economy to 95 MPG.

2.) They're Underinflated
The corollary to overinflated, this condition is not to be confused with a "flat" tire (which is also bad). An underinflated tire doesn't just decrease your MPG, it can also lead to irregular wear. Want to know what the right inflation pressure for your tires is? Don't use the number on the tires — that's just the tire manufacturer's suggested maximum inflation pressure. Instead, check the sticker on the driver's door frame or inside the glovebox for the right pressure. Also, check the owner's manual.

1.) And the number one reason your tires fail is... (it's almost too obvious, but place your bets and check it out here.)

In all seriousness, the points themselves may seem obvious, but PopMech does a good job of explaining the hows and whys behind their top five failure modes, and they might just clue you in on something you've forgotten.

PM: As I mentioned, the Internet geeks are already pumped up about the show—my buddies at Jalopnik are already calling you the "proto-Clarkson," and I'm sure fans of your radio show and accompanying blog have been hammering you about which rides you're pulling out of that stacked garage of yours and onto set. But Top Gear in the UK is kind of an online phenomenon in this country to begin with—it's gotten bigger on YouTube than some of your old Man Show tricks. What do you make of that, and are you as into the, well, insane stunts of the original as we are?
AC: You know, it's funny. I like cars more than I like stunts. The stunts are cool, but I would much rather just see ... I was just watching a rerun and Jeremy had that Aston Martin DBS in the Aston Martin Racing Green and he was turning some hot laps with that thing on an Air Force base they have over there in the UK. For me, as a viewer, in terms of just pure eye candy, I like watching that more than I like them turning a car into an amphibious landing craft or something. That's all well and good, and there's a place for it, but for me it's really about the cars.

The popular kids just are just smitten with the showing of Mercedes-Benz this year. First Popular Science picked the 2006 S-Class as the Grand Award winner among its Best of the New for 2006. Now, Popular Mechanics has named the Merc CLS 500/55 winner in the design category of its Best New Cars and Trucks of 2006. Considering all the trouble some Mercedes cars have had with its electrical systems this past year, we doubt Popular Electronics will chime in on a hat-trick anytime soon.

Mercedes-Benz CLS 500/55 [Popular Mechanics]

Related:
Popular Science Names Mercedes S-Class Best of the New [internal]