[Kolenka]

That is the correct way to use the tranny. This has been discussed before in great length. Anyone who downshifts all the time to slow the vehicle (Auto or Stick) is a fool. Going down long grades is another story. Brakes are cheap, clutches and trannys are not.

I'd like to see some of the researchers tackle CVTs as well. These are built to shift a bit more often than your normal geared transmission, lack a clutch in many cases, and in general wear differently than a geared transmission. While I agree that any shift will provide wear, I don't think we can blindly apply geared transmission logic to belted/disc transmissions.

For example: I can't tell someone to not do this because it will burn out the clutch, since in the case of the Subaru CVT, it uses a torque convertor which is going to see the same wear regardless of what the transmission is doing (in the general case, anyways).

 

[Kolenka]

All transmissions are designed to deliver power in one direction.......Slowing the vehicle is a secondary provision. With the CVT, it may not make a lot of difference which way the strain is going. But it very well could be that it is much more rugged in the power on direction.

Also, torque convertors are directional as well. Many auto trannie failures actually start as torque convertor failures. (When bits start to break loose, they go all through the transmission. In general, any major work on a trannie includes a torque convertor replacement.) Driving the motor with the car is not what they are designed to do. Just sayin'.

Again, brake pads are relatively cheap, and easily replaced. If you want to save your brakes, plan ahead, just take your foot off the gas sooner. Try it. You will be suprized how little you will need your brakes.

I did not put brake pads/shoes on my 4runner until it had 180k on it. Manual trannie, but I don't downshift it to slow, either.

Don't get me wrong, I don't actually do a lot of engine braking, just on long hills, and I'm pretty gentle on the brakes when I can be (traffic sometimes decides otherwise). I'm just wary of applying "common wisdom" on a fundamentally different transmission design without some data to back it up. I'd agree that in the absence of such data, that caution is probably due, but that's different from assuming the same rules apply, and using that as the reason for doing it that way.

Torque being applied in the "wrong direction" leading to additional wear makes some sense, depending on the design of the components. While it only needs to work in one direction, that doesn't mean that the design will wear out faster in the other, but it could. But the downshift itself shouldn't be the reason for the additional wear in a CVT design, not when the torque convertor should still be locked up through the whole engine braking maneuver.

Again, this is why I'd wish there was better data on it to research.