how are you using these? do you use them to slow down the car? is it better to use the breaks or wear down the tranny.

 

I don't know that either will cause a problem, but when I'm actually slowing down for something (car in front, red light, etc.) I use the brakes. Replacing them is cheap...

But I do downshift if I'm catching up to a car too fast (i.e. need to slow down <10 mph), or for a corner if I'm playing on back roads, etc.

 

so it ca put wear on the tranny?

 

Sure - you're using the engine drag and tranny to slow down the car. A better question is "will it screw anything up?", and the answer is "probably not".

 

You can play with the upshift and down shift all you want, it will only shift to the lower or higher gear when it is ready. Have fun with it. It is one big shifter kart.

 

with the rev-match function you are not wearing anything down. Using the downshift function on the AT gearboxes is completely safe since it has the rev-match function. The "wear" in a rev-up portion of braking is just as bad as a rev-up you take your engine through when you accelerate. If you were in an MT that would have been a little different as you would need to know how to rev-match so you don't wear down the clutch. I used the pedals a couple of time to brake myself down, but I usually try to avoid last minute brakes. If I'm approaching a light, I start slowing down in advance by simply taking my foot off the gas pedal.

 

This is exactly correct (good description), but doesn't mean there's no wear/stress on the drivetrain when you do it. As you said, it's wear on the drivetrain.

Like I said though, I do it depending on driving situation, and don't expect any problems.

 

In situations like going down steel hills in long stretches (for example leaving Mt. Rainier), this will be very helpful and avoid overheating the brakes.

 

Going down a long steep hill? I would just use my adaptive cruise control. It does all the breaking for you. Plus speeding up.

 

That's correct. Let me rephrase myself: there is wear on the drivetrain but not "excessive" wear. In other words, you are not causing extra damage that is beyond of what the engine/powertrain were designed for.

In short: wear? -yes | damage? - no.

 

Agreed

 

Keep in mind ... you only get up to 25% braking with ICC on.

 

That's a good point. the ICC brakes with a finite force. Don't expect to rely on that thing to save you in case of an emergency situation.