This is taken from Skip Barber's book. What is downshifting for? "The most frequent (and incorrect) answer is, 'to help slow the car down.'"

Essentially, when I'm on 5th (my lude doesn't have 6th) I do sometimes brake and then shift to neutral when the revs become low but I try very hard to downshift to at least three. That way, I don't have to shift to neutral until my car is reasonably slow. If you're in 6th and you're approaching a stoplight, you'll probably find yourself braking relatively hard to stop both in 6th gear and in neutral. So if I have time I do think it's better to downshift. Especially when you like to cruise, when there's no cars ahead and you see a redlight, downshift to second and go slowly until the light changes, then you don't need to brake nor have to come to a full stop.

Being in a lower gear just gives you better control that's all. If you're in 6th and the light suddenly changes, you'll have to downshift anyways.

 

[QUOTE]Originally posted by hpalmer
[B]



If you match RPM before re-engaging the clutch the wear is very minimal.

 

I've always downshifted to match the current speed of the car -- never to slow the car down. As has been repeated on prior messages, brakes are cheaper than clutches.

One thing I've noticed many manual transmission drivers tend to do is hold the clutch in at long stoplights. Doing this tends to add additional wear to the throwout bearing.

In other words, when stopped for more than a few seconds, I'll put the transmission in neutral (using the clutch) and release the clutch.

Gowgom

 

Could someone explain why holding the clutch IN would cause clutch wear? I thought that when the clutch pedal is depressed, that means it is disengaged. Thanks!

 

When the transmission is in gear and the clutch is depressed, it is true that you aren't wearing the friction plate of the clutch, but that is because the friction plate is being forceably held away from the flywheel by the pressure your foot is applying to the ring of springs connected to the friction plate and its associated throwout bearing.

So you are not wearing the friction plate but are putting a bit of wear on the spring and the throwout bearing.

 

Whelp, i just learned something by reading this thread. I never knew that you got wear by keeping the clutch depressed while sitting at a light. From now on, it neutral for me.

And secondly, I didn't think about the cost of brake pads vs. new clutch!! I always use the downshifting method of braking and was always so proud if I could get the car to an almost complete stop without touching the brake pedal. Looking at that method now and the cost factor, what a jerk I have been.

Thanks a million for the excellent advice. As usual, everyone here is fantastic.

 

[QUOTE]Originally posted by Rasputin314
[B]Could someone explain why holding the clutch IN would cause clutch wear?

 

Matt, you might be right that holding the springs open is no worse (and more likely easier) on them than stretching them out twice at a stoplight. But I have always had the friction compenent of the clutch wear long before the springs did, so in terms of lengthening the life of your clutch, I think it is more important to think about ways you can cutting out friction actions on the clutch that don't really do you any good (such as using the clutch to hold a hill) than worry about springs that don't wear out often.

 

I've always wondered about this:

If you let someone sit in your car (car off) and let him/her depress the clutch would that theoretically wear out the clutch?

 

It's probably a wash between throwout bearing / clutch wear when stopped at a light... I've gotten 90k+ out of clutches with my habits.

As for the engine off question, neither the flywheel / pressure plate assemblies are rotating, so there will be no frictional wear to the clutch or throwout bearing.

Has anyone experienced return spring failure? I only wrench on my own cars as a hobby!

Gowgom