JimV8

I can’t see the value of double clutching a passenger car, rev match yes. Big transmissions have square cut gears and double declutching on downshifts is important and mostly necessary. But upshifts can be done very fast with just a quick release of the accelerator and no clutching at all.

Wild Weasel

If you're using the clutch like a brake pad then you're doing it wrong. The reason to rev match is so you're NOT using the clutch to slow the car. If you do it properly, you shouldn't feel a thing when you let the clutch out.

Imo000

There still going to be strain on the clutch disk that's absolutely not necessary. Also, why even bother when you have brakes to do the same thing that doesn't require much effort? You are not on the race track, why drive like you are on one? #honingyourskills ?

Wild Weasel

Rev matching downshifts isn't just about going fast. It's just the proper way to downshift. If you're in 5th gear and slow down for someone making a turn in front of you... do you just stay in 5th? You can use your brakes to slow down... that's fine. Engine braking is a different debate. But you ARE gonna downshift aren't you?? When you downshift to pass someone on the highway, you rev match. When you downshift when slowing down on the street, you rev match. It's just what you do. My daily is a manual Jeep Wrangler. I rev match.
If you don't, you're simply doing it wrong.

reacp911

Imo000 is an expert on toronto traffic lights, geography, and now shifting.

steam_mill

Hmmmm. Drove to office today. Double clutched my wrangler. I have to say, gears went in much more smoothly. Oh, and I often shift without a clutch.....

reacp911

some years ago, my then new honda civic was not shifting smoothly. I complained to the SA who suggested I take him for a drive. Your problem is you are granny shifting and not exercising the synchos he said. You do this by pushing the lever against the gear gently, but not completing the shift. I did this (and still do it) and it solved the problem

BIG smoke

I used to have to double clutch on some old trucks, and sometimes when the gear oil was not up to temp.
Me? I heal/toe/blip throttle. What I was tought, was transmissions, were for accelerating, brakes were used do decelerating.
Down shifting was preparing for the next gear and accelerating again.
Downshifting in a high compression diesel, the transmission will slow you down. A car @9:1 compression, has little effect, other than impressing the ladies, or passenger.
But I’m a legend in my own mind. I have large following already 🙂

Brakes are cheaper than transmissions. Miss a downshift, that’s a money shift. $$$$$$$ 11k rpm, bend something, or log a over rev.
fuel cut off, work great on acceleration. 5th to 2nd, 💥

Double clutch. Never for me.

Imo000

When I'm slowing down from 5th I just put it in neutral without using the clutch and use the brakes. Don't downshift and use the engine to brake what so ever. I do all my own repairs and know what this does to the clutch so last thing I want is to create more work for myself. As for the highway, on the rare occasion I need to downshift to pass something, I just downshift like everyone else, no rev matching.

Imo000

Someone pi$$ed into your Corn Flakes again this morning?

Wild Weasel

Yeah. That's entirely wrong.
What if you need to suddenly accelerate again??
I mean... you're right in that you're DEFINITELY not wearing the clutch... but engine braking doesn't wear the clutch either... nor does downshifting with proper rev matching.

reacp911

Another anecdote. I was coming back from a date in Hamilton in my '59 beetle. I approached a light, put in the clutch and bang. A pressure plate spring broke. Clutch would no longer release. What to do? Being an engineering student, I put it into gear. Cranked the starter. The car rolled forward and chugged to life. From then on, it was clutchless shifting. Had to repeat at a few lights.

Knowing a few techniques never hurts.

Wild Weasel

Yep. Did the same with my Jeep when the slave cylinder gave up the ghost.

Imo000

Then I put it in gear and off I go but that scenario would be very rare. You are DEFINATELY wearing the clutch under engine load even if you are decelerating. The load on the friction surfaces of the disk and on the disk/dual mass flywheel springs is causing wear.

reacp911

This guy's like the Terminator. He never stops