geekybiker

Just curious how most people drive their manuals. Im still getting used to the new engine.

So...

What RPM do you typically cruise at?

What RPM do you typically shift at?

Do you skip shift (shift 1-3 etc)?

What combined mpg are you getting?


So far for me its
~2000rpm cruise
4k shift in first, 3k in other gears
Skip shift 1-3-5 often
22mpg so far

1995hoo

(1) Usually in the 2000s

(2) Generally around 3500

(3) No

(4) Hard to say "combined" as I usually do all city or all highway. Usually 21 to 22 city, 28 to 30 highway. Current tank, in 230 miles, I'm averaging 18 mph with an average speed of 19 mph.....horrible traffic this month on my morning commute.....

SouthernBoy

1. Depends upon what gear I'm in and the road and traffic conditions. Generally around 2000 - 2500 RPM.

2. My 1-2 shift is usually made around 3500 RPM and the rest of the shifts around 2500 to 3000 RPM. This is due to the fact that regardless of what Acura claims, we do NOT have a true close ratio gear box.

3. I almost never skip shift. And I would strongly advise you do avoid doing this.

4. MPG.. depends upon city (as in work commute) or highway. Generally in the warm months, I get around 25 MPG back and forth to work and over 32 MPG on the highway. My mileage has dropped since I installed Michelin Pilot Sport A/S tires since they have a higher rolling resistance than the stock OEM EL42's did. I have gotten 27.98 for a week of work commuting and a high of 33.94 last year on vacation with the A/C running the entire time. Incidently, these mileage figures I gave are calculated, not read from our MIDs (obviously since they are decimal fractions).

Let me ask you something. Describe how you downshift.

geekybiker

coming from my vette which actually had OEM lock out to shift 1-4 on slow starts its old habit. Any particular reason not to do it? Only real issue is the engine speed difference would higher if you try to shift too quickly AFAIK.


Downshift? I rev match on downshift. Usually on the brakes to start so from there is clutch in, shift to the next gear and bump the gas with my heel as a let out the clutch.

Been driving manuals all my life, just was curious what the most efficient range was for the TL.

LXiFLYBY

(1) Usually in the 2000s

(2) Generally around 3500

(3) No, its very hard on syncros

(4)mostly highway with some city driving mixed in, probably 75% highway, 26mpg

Downshifting i do, and i generally rev match also so it just slips into gear, its easier on syncros and clutches

ragin

I don't mean to hijack, but I have a question about some comments on rev shifting:

Does rev matching == double clutching? I'm thinkin' not (!=).

1) In lower gears I like to cruise at higher rpms.
1st: ~2700 (in my neighborhood, short crawls between stops and bumps)
2nd: ~3000
3rd: ~2500
4th: ~2200
5th: ~2000
6th: irrevelant

2) Again this is gear intensive. Generally ~3000 - 3500

3) Definately not.

4) I've only got 1k miles so far ~23 (75% highway, 25% city)

ndx2

More or less the same here... I tend to keep the RPM a bit above 2k almost all the time.

I usually shift at 3k~ (ya know, take 1st to 20 MPH, 2nd to 30 MPH, etc), except when I'm coming out of corners... i take it up to 4k~.

Surprisingly, I'm averaging 25+ MPG

SouthernBoy

To geekybiker. LXiFLYBY, and ragin;

I just posted this on "Car Talk" and since it is relevant to this topic, I thought I would post it here.

o Let up on the throttle.
o Depress the clutch pedal and start the shift to 3rd gear.
o As you enter the neutral gate and pass through it (do not stop the shifting motion here), release the clutch enough to engage while at the same time blipping the throttle to raise engine speed.
o Depress the clutch again and complete the shift to 3rd.
o Release the clutch.

Yes, this is also known as double clutching and is commonly called rev-matching in today's parlance. The reason that you want to release the clutch while at the same time blipping the throttle in the neutral gate is to spin up the drive gears so that when the shift is actually made, the work the synchronizers must do is minimized. This prolongs their life considerably and makes the downshift very smooth. Keep in mind that when shifting gears, in reality, you are not actually shifting any gears at all. What you are doing is moving collars into hubs and meshing dog teeth. The gears themselves are constant mesh.


To geekybiker;

I am aware that Chevrolet introduced the first-to-fourth "forced" shifting in their Corvettes. Not something I would want since I don't like the car doing what I want or need to do.

The primary reason to avoid skip shifting is due to the greater difference in gear ratios, and therefore gears speeds, between "skipped" gears. Let's say that you want to skip shift from 2nd to 4th gear and you start the shift to 4th after having run the engine up to 4000 RPM. Fourth gear might only run at, say, 2800 RPM at that road speed. So you would need to wait until the engine speed slowed down to less than 2800 RPM since the car would also be slowing down, until you made the shift. Otherwise, the synchronizers would be stressed more than normal for the mesh.


To LXiFLYBY;

Try adding the extra step I mentioned above about releasing the clutch some while blipping the throttle in the neutral gate at the same time and then complete the shift. This will really reduce wear on the synchronizers. Good that you're rev-matching, though.


To ragin;

Rev-matching done without the step I mentioned in the middle of the downshift is not double clutching. However, today the term "rev-matching" is somewhat generic and would generally be considered the same as double clutching by many people.

LXiFLYBY

ill see if it makes a difference. The ecu seems to hold the rpms up in certain situations/conditions that if you just clutch and shift without blipping the throttle at all it engages already rev matched... am i the only one that notices this?

chfields

I shift by feel and sound of the engine, I don't double clutch or rev match, the only time I rev matched is when clutch cable broke and had to shift w/o clutch. Seems to me double clutching and rev matching is unneccesary, I have never had any issues in the 25 yrs I have driven manual trannies....

SouthernBoy

The ECU does this on upshifts. It will tend to hold the RPMs at a lower speed for the next higher gear in the shift. But not for downshifts.

SouthernBoy

I also had to do this with a broke clutch cable on a 1964 Corvair Spyder.. twice. Come to think of it, it wasn't the cable that broke.. it was the small ball joint which fitted into the release fork.

The technique I described for downshifting, while certainly not the only way to downshift, IS the only correct way to downshift. I didn't make this technique up.. I learned it in my very young years, thank God. And I have perfected it to the point where now when I can get into any manual car or truck I can start doing this almost right away. Last year I drove a NASCAR race car for 15 laps at Richmond International Raceway and was even using this technique in that car.

Using this method to downshift, along with a host of other techniques such as not holding the car on a hill with the clutch and not holding the clutch pedal while waiting for a light to change, will greatly extend the life of the clutch assembly. Barring racing, towing, or some other unusual circumstances, you should expect at the very minimum, well over 100,000 miles out of a clutch assembly. In fact over 300,000 miles is not out of the realm of possibility.

The three most stressful and wearing actions on a clutch assembly are using the clutch to hold the car on a hill, over revving while starting off, and downshifting improperly. Obviously racing and towing are VERY hard on the clutch as well but most of us do not do these two things with our TLs.

TL Dude

Exactly the same for me.

mn2trance

Kind of the same question, but this refers to down shifting. Say that you're in mild condition traffic and you're in top gear, but traffic slows down but doesn't completely stop. Do you keep down shifting to the next lower gear in their order or can you just wait to when it gets really slow; e.g., from 65+ MPH to 35 MPH - from 6th to 3rd, but you rev-match doing this? Would this be the same as skip shifting also? If this is the case, then I need to stop doing that when I down shift. However, I don't skip shift when I up shift.

SouthernBoy

I would use my brakes and take the car down to the speed flow, then downshift to an appropriate gear. I should add that I would also be cognizant of conditions where I might need to get into a lower gear more quickly to accelerate in the situation you have described. This is pretty much normal for heavier traffic on freeways and interstates.

SouthernBoy

I would also like to add that I don't always downshift through the gears while coming to a stop light or stop sign. In fact, generally I do not do this. I use the brakes until the RPMs are close to idle, then I just slip the tranny into neutral.

ragin

When you say slip, does that mean pulling it into neutral without pushing the clutch in? I know you can do this in other cars I have driven. I may be wrong, but I would think this is a bad idea.

black label

I won't cause issue's if you know how to shift, but in a performance frame, a double clutching driver will be faster. If you watch footage with sound of Sir Jackie Stewart racing F1 on the old Nurburgring, you will see (hear) him double clutch everytime he downshifts for power. He also skips from 2nd to 4th in certain parts of the track when he is accelarating down hill.

I skip gears all the time in my 03 CL type S 6MT. I can accelerated to a speed good enough to get me a ticket in any state on any highway in 3rd gear. If I'm going 80mph out of 3rd, I just shift to 6th, there is no reason to 4th, 5th then 6th.

In terms of when to shift, it all depends on the application. In town I shift at about 3500-4000. Getting on the highway I shift a fraction of a second before the rev limiter kicks in.

SouthernBoy

No, you should always use the clutch. You're correct.. this would be a bad idea.

geekybiker

double clutching != rev matching. Double clutching is something you only really need to worry about when you dont have synchros. In fact it become imperative then. However if you are double clutching on a synchro gearbox, you're just wasting time. Perhaps you save yourself a little bit of wear on the synchros, but thats about it. The primary purpose of rev matching is so that you dont unsettle the car, and you dont need to release the clutch do to this.

mn2trance

Okay . . . I do all of that when I'm slowing down. I just thought it would be bad for the synchros if I skip shift while down shifting. Sweet! Guess I'm shifting correctly now thanks to your manual techniques.

SouthernBoy

I must disagree with your assessment. While I agree that the original meaning of the term "double clutching" is not rev-matching, rev-matching is part of and absolutely necessary to double clutch. I did say that in today's use of the term "rev-matching" many people take that to mean double clutching.

As for double clutch not being necessary with modern manual transmissions (as in those made for the past 50 years), this is also true. However, it will not only smooth out the downshift but will significantly increase the life of synchronizers because it reduces the load on those components. And if you do not rev-match on a downshift, you are seriously increasing wear on your clutch assembly. Based upon your response, I'm not completely certain you understand my description of this process. Nevertheless, I know for a fact that what I have described is not only beneficial, but is the only correct and proper method to use for downshifting. As I said, I didn't make this up.. I was just very fortunate to have learned it at a young age.

LXiFLYBY

I agree, i rarely engine brake. I think that double clutching in a syncronized gearbox is unnessesary and itll slow down your shifts, but it wont hurt anything, but i agree that rev matching is a MUST. I havent really noticed a shift quality improvement double clutching the TL. I usually save the double clutching for big diesel trucks where its virtually the ONLY way youll shift into the next gear. Alot of them are unsynchronized though

geekybiker

I understand the concepts quite well. I just think you're getting a little mixed up on termonology, that's all. I don't think very many people think referr to double clutching as rev-matching these days unless they are whole unfamiliar with the terms.

Lets just say rev matching is possible without double clutching on a modern syncho transmission and leave it there.

mrodriques

What RPM do you typically cruise at? 1750 -2250

What RPM do you typically shift at? 2100 - 2400

Do you skip shift (shift 1-3 etc)? Never

What combined mpg are you getting? 31 - 34

SouthernBoy

Then I apologize for my inference. However, I am most definitely not mixed up on the terminology, and therefore meaning, of the two terms. I think you're right that people do get the terms mixed up, though.. perhaps more people do this then we think. I also know that some people use the term "rev-matching" do describe the method of downshifting I have described and use. And some of these people are members of this website.

Rev-matching is most definitely possible without double clutching because in the strict sense, they describe two different actions. However, while technically rev-matching does not include double clutching, double clutching always must include rev-matching.

Again, sorry for the inference my friend.

SouthernBoy

Double clutching actually speeds up your downshifts quite a bit over other methods because it allows almost immediate full release (engagement) of the clutch since all of the necessary components would be turning at speeds very close to where they would need to be once full engagement takes place.

Lets say you only rev-match when downshifting which in the strictest definition is this;

o Release foot from throttle.
o Depress the clutch.
o While moving the shifter to the next lower gear, blip the throttle to raise engine RPMs.
o Complete the shift and release the clutch as the RPMs come down to where they should be for the chosen lower gear.

In this description, the partial (or complete) release of the clutch while blipping the throttle as you pass through the neutral gate was left out (commonly called double clutching). Here is what happens inside the transmission when you rev-match as described above.

When you release your foot from the throttle and depress the clutch, you remove the connection between the clutch assembly and the input shaft to the transmission. This input shaft connects to the drive gears. In a constant mesh transmission, all of the gears are in full and constant mesh.. you do NOT shift gears in such a transmission.

Now as you rev the engine while performing the shift you are raising the engine RPMs but since the clutch is still depressed, the drive gears receive no engine power and continue to slow down. As the shifting forks force the synchronizer in the collar of the lower gear to contact the drive gear hub's mating surface the difference in RPMs between these two components is much greater than if they were turning at or near the same speed. This causes friction and therefore wear as the synchronizer and mating surface together match gear speeds for the mesh of the dog teeth.

This is why you want to add that little step of releasing the clutch some, or all, to force engine power to the drive gears so that the hubs and collars are very close to or actually match each other's speeds.

So in a nut shell, rev-matching significantly reduces clutch component wear. Double clutching, or what I would prefer to call synchro-matching reduces wear on the entire assembly including the synchronizers and transmission. As a side benefit, it also prolongs transmission fluid life because far fewer tiny slivers of synchonizer material will be removed from the synchronizers and float around in the fluid. This may also prolong gear and bearing life which is why I said it will prolong the life of your transmission.

subinf

Usually cruise at 2k
Shift a little above 3k
I will only skip downshifts
My combined used to be about 25, now I'm all city, its about 18-20

SouthernBoy

If you skip gears when downshifting (say from 4th to 2nd), rev-matching and double clutch is a must since the difference in ratios is much greater and the stress and wear on the clutch components is far greater as you move down to the lower gears.

subinf

^-I do pretty much what you described above.