I read your recent column about the relative uselessness of...

Dear Car Talk | Dec 01, 1994
Dear Tom and Ray:
Mary
TOM: It's not serious at all, Mary. If your car DIDN'T do this, it would be serious. What was happening is absolutely normal; the transmission was "downshifting."
RAY: If you've ridden a ten speed bicycle, you know that if you're riding along in say, tenth gear, and you suddenly come to a hill, it gets hard to pedal. So what do you do? You shift to a lower gear. And when you downshift to say, first gear, it gets a lot easier to pedal, but suddently your legs are moving at warp speed! Well, the same sort of thing happens in your car.
TOM: If you're going up a hill in second gear, the engine speed---as measured by the tachometer in revolutions per minute---may be 2,000 (your tachometer abbreviates it as 2). When your automatic transmission senses that it's getting too hard for the engine to "push" in that gear, it shifts to a lower gear. And suddenly, in first gear, the engine is turning at 3,000 rpm, even though the car is going the same speed.
RAY: So that's all it is. When your transmission shifts to a lower gear, the engine speed, as measured by the tachometer, increases. And when your transmission shifts to a higher gear, the engine speed decreases.
TOM: And by the way, you two may be the luckiest '87 Escort owners on earth. You get to drive your car without having to hear the hundreds of OTHER noises it makes! 1903
Mary
TOM: It's not serious at all, Mary. If your car DIDN'T do this, it would be serious. What was happening is absolutely normal; the transmission was "downshifting."
RAY: If you've ridden a ten speed bicycle, you know that if you're riding along in say, tenth gear, and you suddenly come to a hill, it gets hard to pedal. So what do you do? You shift to a lower gear. And when you downshift to say, first gear, it gets a lot easier to pedal, but suddently your legs are moving at warp speed! Well, the same sort of thing happens in your car.
TOM: If you're going up a hill in second gear, the engine speed---as measured by the tachometer in revolutions per minute---may be 2,000 (your tachometer abbreviates it as 2). When your automatic transmission senses that it's getting too hard for the engine to "push" in that gear, it shifts to a lower gear. And suddenly, in first gear, the engine is turning at 3,000 rpm, even though the car is going the same speed.
RAY: So that's all it is. When your transmission shifts to a lower gear, the engine speed, as measured by the tachometer, increases. And when your transmission shifts to a higher gear, the engine speed decreases.
TOM: And by the way, you two may be the luckiest '87 Escort owners on earth. You get to drive your car without having to hear the hundreds of OTHER noises it makes! 1903
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