Does Downshifting (Engine Braking) Cause Extra Wear and Tear?
Since the days of taking drivers ed (many years back). I was told that when you encounter a steep or extended downgrade, to conserve your brakes and help increase braking performance it's a good idea to shift from Drive to 2nd (at least on automatic transmissions which is all I've driven).
Still, while the advice seemes valid and for the most part it's helped greatly every so often in winter on hilly areas, on a recent trip through upstate New York, I encountered numerous rural hills so steep and long that when I downshifted, I was hitting 3-3.5k RPM peaking at 4k even as I was doing 40mph and breaking heavily (but steadily) to keep the RPMs in check.
Anyway my main question is that when you see those hills with the signs indicating trucks must downshift, is it also a good idea for people driving sedans and other non-commercial vehicles?
The main reason I ask is because I've heard downshifting saves brake pads but can damage the transmision, so the rationale is to avoid downshifting when possible. I've done this for much of my average driving however I definately would love to get a more solid opinion.