how much does down shifting wear out the clutch, if done properly?

 

If you can match the revs exactly then it doesn't cause any wear. You also should worry about rev matching to protect your synchros

 

^ What Dark said. I downshift all the time, and I have a 15-year-old Toyota Celica with 180,000 miles and the original clutch. Match revs when you downshift and the effect on the clutch is minimal.

 

...it doesn't.

edit: bah I had this thread tabbed in firefox for about 10 minutes, whatever

 

thanks for the info, but what i should have specified was without rev matching....like using the engine comprssion to slow down, that type of down shifting

 

Down shifting at 70mph to third gear, and flooring it, puts a smile on my face.

 

Downshifting does not add any appreciable amount of wear to the clutch. That is a myth. Does it add any? Sure it does. Will it effectively reduce the life of your clutch? It depends on how you drive. I'm at 158,000 on my daily driver and I downshift everywhere. I'm so crazy about downshifting that I'm still on the original set of rear brakes. No clutch issues.

Think about this. When you are downshifting, all you are doing is increasing the speed of a rotating engine assembly. It isn't under a load and relative to the car doesn't weigh very much. It's just dead weight you are slowing down. This isn't that hard. When you are accelerating, this engine is under load providing all of it's power through the clutch and is trying to get 3000+ pounds moving. Sometimes quite quickly. Sometimes people will dump the clutch at high rpms and really put some power through the clutch. Of course this is the fast way to kill it but it usually does it. Downshifting is nothing to it. I don't rev match. I slowly ease into the clutch until the engine's rpms get where I want. I use the engine as a dynamic brake. It works great and saves fuel and brakes. It doesn't do anything appreciable to the clutch.

 

^me too

I guess you mean engine-breaking...I do it sometimes, but not often. I don't see the point. Wear is put on your clutch and synchros whenever you use them. During engine breaking, you're using them a lot, even if you're doing it right. It probably doesn't hurt your car too much...but I'd rather use up my brake pads.

 

Then take what I said before and apply the contrary

Figure out heal 'n' toe down shifts.

 

i already do, but thanks for the tip.


Figure out heal 'n' toe down shifts.[/QUOTE]

 

Downshifting also reduces brake dust.

Very important after an hour or two washing and waxing the car.

 

I don't match revs either, I do the same.

-Cody

 

Mu ha haaaaaaa

 

Likewise. Never had a clutch problem. My day is made that I'm doing the same thing as rotarygod! As I've said many times, your clutch is not made out of crystal.

 

I'd venture to say that shifting is at least 50% of what makes driving the rx-8 fun.

 

The other 50 is tackling the twisties .

-Cody