I don't think anyone into race tracking is really going to be worried about accelerated clutch wear when down-shifting on the street.
Unfortunatly, anything made to be used also comes with a wear factor. Decide for your self what is acceptable and what isn't. Downshifting seems acceptable to me but perhaps for others it may not.

 

The point of staying in gear is to not upset the balance of the car or unnecessarily shift the weight of the car by putting the clutch in. This can induce a spin or other potential unsafe reaction from the car. However, there are a few specific circumstances that will cause this to happen. Being on a track, taking a fast turn, and clutching at the apex can induce a spin. Since the clutch was engaged the balance of the car can be upset and it can be hard to control once the spin is induced.

But we're talking about city driving here. Take an example: I'm going 45mph in 4th gear, cars in front of me and behind me. 100 yards ahead I see a light go from yellow to red, I put the car in neutral after I've left it in 4th gear as long as I can before the engine starts to lug (usually around 2000 RPMs). At this point when I put the clutch in I'm doing MAYBE 20mph. I don't care if the car is in or out of gear, it's not going to induce some hellacious spin if I suddenly swerve to avoid a rabid soccer mom on her phone with 5 kids in the back of an SUV.

This is the point I'm making here. I'm saying the margin of safety for leaving the car in gear at such trivial speeds is pointless. Now, for what it's worth I usually do downshift rev match on offramps. Usually because the car is still going pretty fast (60+ MPH) and, like you mention, I want to car to behave predictably if I have to avoid an accident. But in the city, where speeds remain very low I think it's insignificant if you leave the car in neutral just before you come to a stop at a light.

 

just keep it in gear while applying the brakes. Then put it in neutral before the enging starts to bog ~ 20mph and come to a stop. What's so hard about that. You'll only be "out of control" for 25 feet.

 

I2I- Funny you should mention tha fact that having control of the car can save you from an accident.
Returning to Fla from Calif. last week, something happened on the Interstate which called for heavy breaking and quick downshifts.
The car directly behind me was destined to rear end me if I didn't have the ability to immediatly pull foward an extra few feet.
If the car had been in neutral, I'd have been fU'kd.

 

Downshift when needed with purpose or just to have fun.

It will save on brake pad wear, but increases clutch wear.

Brake pad replacement much cheaper than clutch replacement.

Do the math and have fun.

 

gunderwood Posted: Jan 12 2007, 04:46 PM
If you mean the release bearing (just the one) then maybe, if you keep the clutch disengaged for half an hour or so.
The release bearing (or throw-out bearing) isn't IN the transmission.
With "IN the transmission" I mean lubricated by transmission oil.

Waiting a minute (and that's LONG!) for an unfamiliar traffic light to turn green with the clutch disengaged and in 1st gear will do no harm IMO.
When the light suddenly turns green while in neutral, and you disengage the clutch and put it in 1st gear (all in one motion) you'll get the "first gear clunck" again.


CKit Posted on Jan 12 2007, 06:15 PM

 

being in the appropriate gear for the speed you are traveling, whether slowing down or not, it the correct method for optimum safety. If you need to avoid danger while slowing down by hitting the throttle, but youre going 20mph in 4th gear, you are screwed. This happened to me when I first started driving back in the day. Its not fun knowing I could have avoided an accident had I been in the correct gear.

 

for daily driving its best to leave it in 6th while braking then go into neutral before it bogs. downshifting (engine-braking) is a good way to wear out your tranny. why not just kill your brake pads instead, its a lot cheaper to replace.

 

Why does everyone assume that downshifting wears out your transmission?

someone should tell that to my 235,000 mile 1988 Prelude. because I've downshifted to a stop on it since 127,000 when I swapped in the 5 spd in 2000, and it's still working fine. And I autocrossed it from 2001-2004. No problems for me...

A correct blip of the throttle, thereby matching engine & transmission speeds, will not accelerate clutch or transmission wear.

 

If you are rev-matching so well that you can shift between the gears without depressing the clutch then maybe so.

If you are using the clutch 3 times to downshift to a stop OR use the clutch one time and then the brakes to stop, you are engaging the clutch 3 times instead of once.

Everytime you engage the clutch, there will be wear, as there is friction, rubbing, and slipping happening on the plate. It can be minimized with a rev-match, but it will still occur.

Now if you have 20 stops per day where you do this, with 2 extra clutch engagments per stop, you are causing wear 40 times more often per day (but saving wear on the brake pads).

In a year, you will have caused friction on the clutch plate 14,600 times more often.