Is idling the engine with the AC on hurting my 150k mile Corolla?

Dear Car Talk | Jan 01, 1999
Dear Tom and Ray:
always goes to the grocery store with me. While I shop, he stays in the car
reading books. The problem is in the summer. In order to keep cool, he keeps the
engine running and the air conditioner on. I spend between 30 and 60 minutes in
the store. Our car is a 1988 Corolla with 150,000 miles on it. Is this practice
doing bad things to the car? -- Joan
TOM: Joan, if he enjoys your company so much, why isn't he in the grocery store
WITH you? Seems to me he could stay nice and cool by hanging out in the frozen-
food section.
RAY: Actually, he's not doing any harm to the car. Idling creates very little
wear and tear on the engine. Ask my brother. He's the King of Idling.
TOM: When the engine is idling, it's turning slowly. The explosions in the
cylinders are smaller, it's running cool and there's very little load on the
bearings. In fact, if I had to take a wild guess, I'd say an hour of idling is
equivalent to about five or 10 minutes of highway driving in terms of wear and
tear (someone who's done a Ph.D. dissertation on this will send us the exact
figures).
RAY: It does waste a little gas and does create a little more pollution, but
idling in the parking lot for an hour won't damage the car.
TOM: And think of the alternative, Joan. Without the air conditioning, after an
hour in the car, his BO would wilt your nice, fresh, newly purchased lettuce!
always goes to the grocery store with me. While I shop, he stays in the car
reading books. The problem is in the summer. In order to keep cool, he keeps the
engine running and the air conditioner on. I spend between 30 and 60 minutes in
the store. Our car is a 1988 Corolla with 150,000 miles on it. Is this practice
doing bad things to the car? -- Joan
TOM: Joan, if he enjoys your company so much, why isn't he in the grocery store
WITH you? Seems to me he could stay nice and cool by hanging out in the frozen-
food section.
RAY: Actually, he's not doing any harm to the car. Idling creates very little
wear and tear on the engine. Ask my brother. He's the King of Idling.
TOM: When the engine is idling, it's turning slowly. The explosions in the
cylinders are smaller, it's running cool and there's very little load on the
bearings. In fact, if I had to take a wild guess, I'd say an hour of idling is
equivalent to about five or 10 minutes of highway driving in terms of wear and
tear (someone who's done a Ph.D. dissertation on this will send us the exact
figures).
RAY: It does waste a little gas and does create a little more pollution, but
idling in the parking lot for an hour won't damage the car.
TOM: And think of the alternative, Joan. Without the air conditioning, after an
hour in the car, his BO would wilt your nice, fresh, newly purchased lettuce!
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