Overdrive: Increased transmission wear or not?

[braverichard]

This just came to my mind today. My girlfriend and I flew to Baltimore to pick up her new Lexus RX400H - well actually, the car is used, but with just 900 miles on the clock when we bought it. The couple that bought it new just two months ago just stumbled across a great financial need and decided to sell it. We just arrived back here after driving it all the way back. The car's transmission has a very, very tall overdrive gear. It does 80mph at 2,100 rpm or so. As I drove through the Apalachian mountains at high speeds of around 90mph, it constantly had to downshift to a lower gear to get more power. This continued even after we left that mountain range and drove on flat highways. Basically, anytime I needed power to pass another vehicle or for any other reason the transmission downshifted. The downshifts were smooth, no questions about that, but I just started wondering if such a tall overdrive would increase wear on the transmission as it constantly had to downshift, perhaps more often than it would if the engine was spinning higher with more power available without a downshift.

I just want to hear your opinions on this. I'm sure all the automakers know what they are doing by introducing overdrive in all cars today, but it was a thought I decided to bring out for discussion.