Will using 5th gear "loosen up" my high mileage engine?

Dear Car Talk | Oct 01, 2001
Dear Tom and Ray:
RAY: Let me guess, Richard. This guy's brother-in-law sells new Toyotas. And he's working on commission?
TOM: You've got 307,000 miles on your car, and he's going to tell YOU how to make your engine last? I don't think so.
RAY: He's probably concerned about "lugging" the engine. You probably know what lugging is, right? It's when you try to accelerate in too low a gear and the car bucks and labors and pings until you either downshift or get up to an appropriate speed for that gear.
TOM: And lugging IS bad for your engine, especially an old engine, because it causes overheating.
RAY: But using Fifth gear correctly -- as I'm sure you do -- at high speed on a level road, is actually good for the engine. It allows the engine to run more slowly and turn fewer revolutions per mile. And the fewer times it turns, the longer it lasts.
RAY: So I think YOU'RE clearly the expert on how to make an engine last forever, Richard. We'll look for your book when it comes out.
RAY: Let me guess, Richard. This guy's brother-in-law sells new Toyotas. And he's working on commission?
TOM: You've got 307,000 miles on your car, and he's going to tell YOU how to make your engine last? I don't think so.
RAY: He's probably concerned about "lugging" the engine. You probably know what lugging is, right? It's when you try to accelerate in too low a gear and the car bucks and labors and pings until you either downshift or get up to an appropriate speed for that gear.
TOM: And lugging IS bad for your engine, especially an old engine, because it causes overheating.
RAY: But using Fifth gear correctly -- as I'm sure you do -- at high speed on a level road, is actually good for the engine. It allows the engine to run more slowly and turn fewer revolutions per mile. And the fewer times it turns, the longer it lasts.
RAY: So I think YOU'RE clearly the expert on how to make an engine last forever, Richard. We'll look for your book when it comes out.
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