Skipping gears on a manual transmission

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

Chrono

Diamond Member
Jan 2, 2001
4,959
0
71
When I upshift, I always cycle through all gears regardless, and the only reason why is because I want to be in the best gear to be gas efficient yet still have the powerband to move my ass out of the way in case something happens in front of me. I only rev match when I downshift. Sometimes I do the unnecessary double clutch heel-and-toe when, let's say, I go from 6th to 4th gear, or basically anytime I jump two gears down. Of course this entirely depends on what kinda car you drive and what type of clutch it has installed. A lot of cars are more forgiving than say the STI that I drive.
 

Viperoni

Lifer
Jan 4, 2000
11,084
1
71
Originally posted by: Demon-Xanth
<-- can easily go from 10-90 in third, can grudgingly go from 0-105MPH. (some significant clutch slippage to redline)

What do you mean bysignificant cluch slippage?
All you need to slip the clutch for is so you can get moving to say 10mph, then fully release the clutch and you're good...

 

Scouzer

Lifer
Jun 3, 2001
10,358
5
0
Sorry guys, I used the wrong term.

What I had intended was that when I shift gears I make them long shifts to make the revs fall to what they'd be in that gear.

For example, if I skip from 2nd to 4th, I let the revs naturally fall to about 1500rpm which would be what the motor wants to be at after skipping 3rd.

I did not realize that rev-matching doesn't mean this...:)
 

psteng19

Diamond Member
Dec 9, 2000
5,953
0
0
Originally posted by: spidey07
No damage to your tranny whatsoever. Whoever told you that is an idiot.

However if you're going for fuel economy it doesn't make sense to skip gears - just keep the motor in it's ideal RPM range.

More wear on the synchros if revs not matched.
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
Originally posted by: Scouzer
I did not realize that rev-matching doesn't mean this...:)

That's EXACTLY what rev-matching means. Matching the revolutions of the motor to the input of the transmission.

Most people don't know how to upshift properly and leave the RPMs higher than they need to be resulting in a not so smooth shift or clutch slippage.
 

Scouzer

Lifer
Jun 3, 2001
10,358
5
0
Another query: Is it bad to drive along with revs quite low? Around town if I keep it in 5th it only turns about 1100rpm, which seems a bit low to me.
 

chris7b

Senior member
Nov 11, 2003
390
0
0
Why would you need to step on the pedal to match when skipping gears? If anything you need to lay off the gas for your RPMS to drop and match.
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
Originally posted by: Scouzer
Another query: Is it bad to drive along with revs quite low? Around town if I keep it in 5th it only turns about 1100rpm, which seems a bit low to me.

You're lugging the motor. Don't do that.
 

Mr N8

Diamond Member
Dec 3, 2001
8,793
0
76
I hope it's not a problem. :) When I'm getting on the interstate or pulling onto a 55mph road, I often start in 2nd, shift to 3rd and then 5th.
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
Originally posted by: Viperoni
Originally posted by: Demon-Xanth
<-- can easily go from 10-90 in third, can grudgingly go from 0-105MPH. (some significant clutch slippage to redline)

What do you mean bysignificant cluch slippage?
All you need to slip the clutch for is so you can get moving to say 10mph, then fully release the clutch and you're good...

That's what I mean, it's alot harder on the clutch than 1st and 2nd gears though. Causes wear that doesn't need to be done.
 

jupiter57

Diamond Member
Nov 18, 2001
4,600
3
71
Originally posted by: psteng19
Originally posted by: spidey07
No damage to your tranny whatsoever. Whoever told you that is an idiot.

However if you're going for fuel economy it doesn't make sense to skip gears - just keep the motor in it's ideal RPM range.

More wear on the synchros if revs not matched.

You will get little or practically no wear on your synchronizers if you don't "Powershift, or slam the gears.
In other words, just shift normally.
 

blckgrffn

Diamond Member
May 1, 2003
9,676
4,308
136
www.teamjuchems.com
Originally posted by: AMCRambler
I would think if you're not using all the gears you'd be hurting your fuel mileage. You'll be revving higher in the first gear so that you're not lugging the engine in the next gear. Now for 4th gear to 6th gear I wouldn't think that would be much of a difference because you're already crusing. But the lower gears would be where you see the wasted gas. Now downshifting, I skip gears a lot. If I'm coming up to a light or stop sign, I'll just slow down with the brakes and then downshift from 4th to 2nd when I've slowed down enough. My reasoning on that is, brakes are cheaper to replace than a clutch.

Yep. For this reason, I rarely even break with the clutch at a stop sign or light. Only when I know that I'll be using the engine again, ala onramps and such, will I blip the throttle and drop it into second or third.

Relatively speaking, break pads are cheap.
 

Viperoni

Lifer
Jan 4, 2000
11,084
1
71
Originally posted by: Demon-Xanth
Originally posted by: Viperoni
Originally posted by: Demon-Xanth
<-- can easily go from 10-90 in third, can grudgingly go from 0-105MPH. (some significant clutch slippage to redline)

What do you mean bysignificant cluch slippage?
All you need to slip the clutch for is so you can get moving to say 10mph, then fully release the clutch and you're good...

That's what I mean, it's alot harder on the clutch than 1st and 2nd gears though. Causes wear that doesn't need to be done.

Oh ok, funny wording :)
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
36
91
Originally posted by: paulxcook
Also, rev matching means you're burning more gas to get up to a higher rpm to skip the gear you're skipping in order to save gas. Huh.
First, blipping the throttle uses MUCH less gasoline than running through a gear. There's a helluva lot less load on the engine when it's disconnected from the gearbox.

Second, you don't need to blip the throttle for upshifts, so it's a moot point.

ZV
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
36
91
Originally posted by: paulxcook
Well, you're trying to get up to a speed at which you can shift into 4th from 2nd. So you press on the gas, and up go the RPMs.
For slow cruising where you don't need throttle response, you can go into 4th very early. At the same time you'd normally shift out of 2nd actually.

ZV
 

AdamK47

Lifer
Oct 9, 1999
15,675
3,529
136
Originally posted by: JMWarren
Some GM transmissions force you to if you're not near WOT. I can't see it causing any problems.

It has little to do with throttle It engages under 2500 RPM. I shift at 3K anyways, so I avoid the skipshift 95% of the time. When it does force me from 1st to 4th it bogs like crazy though.
 
Jan 31, 2002
40,819
2
0
Originally posted by: AdamK47
It has little to do with throttle It engages under 2500 RPM. I shift at 3K anyways, so I avoid the skipshift 95% of the time. When it does force me from 1st to 4th it bogs like crazy though.

Get a $20 CAGS-Killer ... for each car. ;)

- M4H
 

jagec

Lifer
Apr 30, 2004
24,442
6
81
Originally posted by: timxpx
do people still even rev match in cars that were made in the last 30 years?

To keep their synchros happy, obviously. The difference between now and then is that you don't have to be as good at it. You don't really have to do it at all unless you're skipping gears (like the OP), or downshifting, especially into a low gear.

OP: Skipping gears is not a problem at all for your transmission, but accelerating to a high RPM in 1->2 then skipping to 5th is less fuel-efficient, but a lot slower, than shifting 1->2->3->4->5 at a reasonable RPM. I only do it when I'm getting up to speed on a freeway onramp (I don't like to merge at under the limit, because I feel that's a dick move to everyone in the right lane), but I don't kid myself about saving fuel while doing so.

When I ride the bike, I can do the whole 1->2->65mph->3456 thing while still getting great mileage:p
 

3chordcharlie

Diamond Member
Mar 30, 2004
9,859
1
81
Originally posted by: AMCRambler
Originally posted by: 3chordcharlie
Originally posted by: paulxcook
I don't skip, mainly because I've never had a reason to, or wanted to. Why would there be a 3rd gear if you didn't need it?

Also, rev matching means you're burning more gas to get up to a higher rpm to skip the gear you're skipping in order to save gas. Huh.

Care to explain why you would need more RPM for a higher gear?

You will have to rev the previous gear higher so that when you skip the next gear you are still in the torque band for the gear you shift to. Otherwise you're lugging your motor when you shift.

I'm a little more utilitarian than that, which is to say I never spin up one gear just for the sake of being able to skip the next one.

I do however put the transmission in the right gear for what it is currently doing, and sometimes (like after accelerating to merge) that means skipping a gear rather than pointlessly shifting twice.