Who's asking: Kathleen McLaughlin Jacobson, Los Angeles, CA
Kathleen asks this in response to the "Sopranos" series finale, during which this happened to AJ's vehicle.
But it's an example of how popular entertainment can save lives, because this can and does happen. I've seen it -- not with an SUV, but a sporty little European roadster. Parked in a Middleburg hayfield on a dry October afternoon, it went up in flames before anyone even realized it was smoking.
It was a steeplechase race meeting. My friends and I were sitting around on a blanket in the midfield, drinking wine and passing a hat for dollar bets, when we saw the black cloud rising from the parking lot. It was between races, so the whole crowd moved over to see what was going on: the two-seater was burning merrily away, and everyone who'd parked anywhere nearby rushed to move their cars before the fire could spread. The fire department responded quickly, and no other cars burned, although the five or six surrounding the burning car were probably totaled by smoke and water damage.
What causes this is the catalytic converter, a portion of the car's exhaust system that forces the car's exhaust through platinum-rhodium and platinum-palladium catalysts in order to remove carbon monoxide and nitrogen oxides. This process turns toxic gases into carbon dioxide and water, and as with any process that compresses gases, it gets hot. Really hot. 1800F hot.
This is why you shouldn't drive your car through a pile of dry leaves, and you shouldn't park any vehicle over something that might be a fire hazard. Most of us know instinctively that parking in a pile of dry leaves isn't a great idea -- but SUV drivers don't always know they're parking over flammable materials, because the cars are so much higher off the ground. Also, some SUV drivers seem to think that "off-road" means "nature-proof," as if these vehicles were somehow exempt from the normal rules of physics.
I'm not a fan of SUVs ... unless you're a park ranger. Some people in Maine genuinely need them. No one in Los Angeles does, and certainly -- as he discovered -- AJ Soprano didn't.