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Author Topic: neutral gear vs drive gear when at red light Back to Topics
cricsync

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Message Posted: Jun 11, 2013 1:58:13 PM

Will you save gas if you shift your car to Neutral gear when you stop by at red light rather than keep it in drive gear?
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dontuknowOH
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Message Posted: Oct 2, 2013 12:57:22 AM

There are a lot of costly questions, like maybe staying down on the go-pedal or often still accelerating up to a visible red light then using the brakes heavily to usually stop/slow. Then the cost hangs pretentious on when the brakes wear needing repaired or may possible fail.

Failing again can be a question of driver error or brake mechanical error/failure. The same goes for worrying about having a flat tire only if one drives or not, saying I've noticed maybe just a few drivers being not too practicable 24-7 Where/wear it happens everywhere...
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GrumpyCat
Champion Author Alabama

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Message Posted: Sep 30, 2013 10:40:40 AM

You might. But especially with an automatic there is the question of whether more wear of shifting in and out of gear costs less to repair than the cost of fuel saved?
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Dale Jr.
Champion Author Illinois

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Message Posted: Sep 30, 2013 9:15:09 AM

My vehicles are automatic so I leave it in drive.
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Glasman
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Message Posted: Sep 30, 2013 8:45:59 AM

yes and it's easier on the tranny and drive train.
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Floridaman2013
Champion Author Florida

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Message Posted: Sep 22, 2013 5:16:11 AM

I only shift to neutral when at a long stop or the transmission has been working hard (towing) so it can cool down, especially when waiting for trains. In high heat and sitting still in drive, the transmission fluid gets hot so keeping in neutral in those occasions will keep the fluid cooler, less wear on the seals.
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Camry05
All-Star Author Indiana

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Message Posted: Sep 22, 2013 3:57:08 AM

Drive
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dontuknowOH
Champion Author Ohio

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Message Posted: Sep 20, 2013 1:15:39 AM

My daily driver will soon be 13 years old, it gets N... upon coming to a red stop for a reasonable two or 3 minute wait, that improves my mileage over the long haul month to month

The other econo vehicle doesn't benefit waiting at a red light it's tranny has newer technology, and no appreciable idle load when stopped idling in drive mode. There is at least a 10+ mile per gal. difference between the two vehicles. partly due to different engine size and one is AWD V/S TWD.

Total weight being different and improved aerodynamics and extra gearing is a factor for the better mileage also city or highway driving.
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carinthuist
Champion Author San Francisco

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Message Posted: Sep 19, 2013 8:41:10 PM

Drive only
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GrizzlyRaptor
Sophomore Author Sacramento

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Message Posted: Sep 19, 2013 6:38:46 PM

Drive.
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Camry05
All-Star Author Indiana

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Message Posted: Sep 19, 2013 6:01:41 PM

in an automatic transmission, it is better to keep it in D when stopping at a light. Better for the brakes and mileage
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Houckster
Champion Author Atlanta

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Message Posted: Sep 10, 2013 2:58:27 PM

Recently I bought a product called Ethanol Defense made by Bell Labs and now they send me newsletters with advice for saving fuel. One of those suggestions was to put the automatic in neutral at stoplights. Their reasoning was that most transmissions are pushing the car forward so putting the trans in neutral will save fuel.

When I drive our Toyota Camry, I don't see any tendency for the car to move forward so I think this suggestion would not save any noticeable amount of fuel but if you have to keep your foot on the brake at stoplights, this might be worth trying. I'd also think getting the transmission checked would be worthwhile.

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Zennyboy
Veteran Author Toronto

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Message Posted: Sep 10, 2013 11:16:52 AM

n
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dontuknowOH
Champion Author Ohio

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Message Posted: Sep 10, 2013 10:22:55 AM

Often N.... Depends on amount of traffic, how crowded the stopped lanes are also the squeeze up pattern while waiting.
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randy3116
Champion Author Tennessee

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Message Posted: Sep 10, 2013 9:16:04 AM

mine is a 6-speed manual and I do shift to neutral at traffic lights. I do, though, stay prepared to clutch and shift to move out of the way in case someone is not slowing down/stopping behind me.
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dontuknowOH
Champion Author Ohio

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Message Posted: Aug 9, 2013 8:36:01 AM

mybigtruck; I can agree on those savings you mentioned... Most drivers still think about vehicles they possible owned back in the 60, 70, 80's and their experiences with those vehicles.

A lot of newer engineering has replaced/superceded those models referring to under-hood engine operations of the modern engine, they operate by OEM programming to a large extent with some driver's choices = results that = ?..?.. then more ?.. ?.. older thoughts. How about a portable porta- potty with a solar powered Robot Sanitary Attendant, on duty! LOL!
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mybigtruck
Champion Author San Jose

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Message Posted: Aug 9, 2013 3:43:30 AM

It does. I monitored fuel rate idling in drive versus neutral. Idling in neutral does indeed consume less fuel.
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HotRod10
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Message Posted: Aug 8, 2013 1:58:05 PM

"you are better off turning off your car"

True, that would actually save fuel, as opposed to shifting into neutral, which is about a wash with just leaving it in gear.

How much would you save? With a modern fuel-injected vehicle, the consensus is that the break-even point is about 10 seconds. Beyond that you're saving gas, but how much? Although it seems longer, almost all stoplights cycle in under a minute; so for about 50 seconds (or less) the engine is not idling. Now, from my my survey here on the GB Forums, warm idle on my little Metro burns about 0.13 gal/hr. and others up to 0.40 gal/hr. At the high end, that's .4 * 50/60/60 = .00555 gallons. At $4/gal, you save 2 cents, or enough gas to go about 800 feet. I wouldn't have to think very hard to find a better way to save that much gas, and I won't be sitting there with people honking at me after the light turns green and they're waiting for me to start my car and go.

Btw, how much does a starter cost for your car? If you get 10,000 starts out of yours (which is about twice what I got out of my last one), you might break even (if you replace it yourself, not even close if you have to pay a mechanic).

[Edited by: HotRod10 at 8/8/2013 2:03:39 PM EST]
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waynecz
Champion Author Mississippi

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Message Posted: Aug 7, 2013 11:47:52 PM

you are better off turning off your car, that is essentially how a hybrid gets a lot of its gas savings hence higher mileage
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HotRod10
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Message Posted: Aug 7, 2013 7:08:04 PM

I don't believe an AT is built to be constantly shifted between Drive and Neutral; it has a torque converter in order to make shifting into Neutral unnecessary. I would not risk damage to a $2000-$4000 transmission to possibly save a few cents at the gas pump.
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dontuknowOH
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Message Posted: Aug 7, 2013 5:49:07 PM

I can agree with HotRod10... about there being no stress at correct idle speed when in drive and still motion.

I also think one can't compare the wear/tear of a manual dry clutch with the wear on multiple disc wet clutches that are helped to cool by fluid. Rather bathed in fluid (under normal circumstances)fluid which draws damaging heat away and lubricating at the same time.

These automatic clutches are in constant operation as the tranny shifts up/down through the gears to carry a smooth shift when changing gear ratio transition. The drive torque is then high when those clutches operate, still keeping a smooth shift transition between gear changes.

The normal std. clutch often gets slipped a lot when start-offs occur, during heavy loads or up-hill starts more wear. Heat builds if slipped too much each time glazing of the dual-faced clutch disk and flywheel surface takes place even stress cracks can develop after heavy use. Results are a slipping clutch waiting to die, along with a throw-out and pilot bearing failing, and maybe a pressure-plate also, also a ring starter gear some cases.

Auto/Trannies built to shift more solid with increased Line pressure/servo action, extra cooling of the fluid helps the clutches last, but heavy trailer towing, multiple uphill downhill use or extreme heavy loading stresses the automatics to a rebuild later. Yes leaks, their common but heat/severe driveline shock destroys and so does lack of fluid.

I'm just saying when the Engine rpms are up that's when the tranny and driveline is getting higher torque stress not at idle, and A.. clutch tangs are made of hard material, stay lubed, get a lot of pressure on the friction surfaces on a reg. basis going threw the normal A.. shifting process. Done...... "dinner" waiting!
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CoolCancerian
Rookie Author New Jersey

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Message Posted: Aug 7, 2013 2:13:16 PM

Nope, with an auto.
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krazkar
Champion Author Calgary

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Message Posted: Aug 7, 2013 1:48:41 PM

When I had a manual, yes.

With an Automatic, no. Driving an auto has dumbed me down so much that I would forget to put it back into drive when the light turns green
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hoopitup2000
Champion Author Virginia

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Message Posted: Aug 7, 2013 1:31:51 PM

Yes, manual transmission
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HotRod10
Champion Author Wyoming

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Message Posted: Aug 7, 2013 1:28:31 PM

"Might not save gas but you will take the tension off the drive train and save your transmission"

If your transmission is working right and your idle speed is set correctly, there shouldn't be any stress on the drive train. The torque converter takes care of allowing the engine to keep turning without turning the transmission input shaft; any "tension" on the drive train is normal and considerably less idling than it is while driving. Shifting between D and N over and over is what will kill the transmission, because you're engaging and disengaging the clutches. They wear out just like the clutch in a manual.
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dontuknowOH
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Message Posted: Aug 3, 2013 11:30:34 AM

Trying to understand any savings by dropping out of drive at a long light is a bit... to explain on a technical basis. I would say that to own an automatic tranny equipped vehicle the first thing is to realize that doing so is a convenience and there is an extra cost for convenience of about any kind of ownership.

Vehicles that have automatics eliminate constant driver required shifting, also the foot clutch work during traffic travels/motion. The automatic clutch function/tranny shifts come at an extra cost top the owner/driver.

When a vehicle is stopped and idle/running with other conveniences turned on there is an extra fuel cost for that energy being used up whether its for safety or not.

Todays automatics get close or even better mileage compared to the std. trannies of past years that is on the average results. Past carbureted vehicles had a pump-shot enrichment squirting a stream of extra fuel into the engine each time the go-pedal had a pressed stroke during manual shifting in each gear(like a Kid's water pistol)on each trigger pull).

EFI/ECM design is an advantage to that pre-system, still realize when your vehicle is stopped/running in drive mode then the automatic clutch/and tranny is a convenience cost when the brakes are held on to prevent movement. Yes the engine is producing HP output then at Idle at a fuel cost, and that can vary.... by your habits of choice/driving.

Automatic clutch referring to the (torque converter) which is slipping away engine HP cost at Idle when in drive motionless stopped. Just MYOP...
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BigHorne1
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Message Posted: Aug 3, 2013 9:54:49 AM

ON a manual it helps the clutch and you clutch foot. For an automatic it does nothing.
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WES03
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Message Posted: Aug 3, 2013 9:12:09 AM

Are we talking auto or manual here?
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ranger2k
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Message Posted: Aug 2, 2013 1:39:57 PM

yes, its nicer to the transmission
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lyanMI
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Message Posted: Aug 2, 2013 10:40:18 AM

I do it some times but didn't see much impact
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dassfg
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Message Posted: Aug 2, 2013 8:14:03 AM

Might not save gas but you will take the tension off the drive train and save your transmission
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Dennis783
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Message Posted: Aug 2, 2013 7:54:31 AM

drive, it doesn't save much and rish trying to take off with car not in gear
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Boyrr
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Message Posted: Aug 2, 2013 6:29:58 AM

not needed, saves nothing
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cools1611
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Message Posted: Jul 31, 2013 12:41:25 PM

I started doing this recently. Not sure if it helps.
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OceanArcher
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Message Posted: Jul 31, 2013 11:22:23 AM

I have never burned out a clutch throwout bearing while sitting at a traffic light.
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WES03
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Message Posted: Jul 29, 2013 8:42:20 AM

Yes always. Not doing so would burn up the throw-out bearing in no time.
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cv
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Message Posted: Jul 29, 2013 6:29:41 AM

Sometimes I do, but rarely.
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dontuknowOH
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Message Posted: Jul 28, 2013 10:18:04 PM

I'm sort of a "lube nut" I have always thought that a little grease/lube oil goes a long way to prevent wear on anything. So I keep most any piece of machinery in motion checked and lubed at the moving parts, dry or wet lubed.

When driving a std. shift vehicle, I always kept the Go-pedal Linkage in smooth performance condition, I then was able to slip out of gear non-clutching on a deceleration to a stop, simply by easing off the go-pedal until the drive-train torque was 0 with the engine rpms.

After stopped I re-clutched to go back into gear, this is only possible with a neat operating smooth go-pedal and good clutch operation combined. Some sport cars have that advantage in design an if well maintained. Yes saved some fuel also.
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jarvisd39
All-Star Author El Paso

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Message Posted: Jul 26, 2013 8:06:08 PM

First, if you're not moving but your engine is running, you're getting zero miles per gallon. While it won't save you a significant amount of gas, even over the course of a year, idling at a traffic light (or while waiting to clear a construction site or for a passing train) does use fuel.

However, the reason it's better to shift into neutral (versus remain in a drive gear) is that shifting into neutral (whether you're driving an automatic or manual transmission) calms down your engine, which in turn saves gas (or, actually, drains less gas rather than saves gas). Said another way, keeping an automatic transmission in Drive puts an extra load on it, which drains fuel, whereasw in neutral it's resting -- or at least as close to rest as an automatic ever gets. This shift is even more important when the air conditioner is running, so the engine doesn't have to strain so hard while idling. A manual transmission should be shifted to neutral at every stop.

To use the mile-long freigh train example, many (most?) drivest keep their engines running. A minute of idling, however, consumes more gas than a restart.
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RedWings44
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Message Posted: Jul 26, 2013 12:20:29 PM

One is running lower RPM but with more effort. I will say no since it is essentially burning the same amount of gas. However, if it does save anything, it likely isn't really noticeable or going to make a difference.
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HotRod10
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Message Posted: Jul 26, 2013 10:48:15 AM

If it saves anything at all, it's not worth having to replace the transmission.
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dontuknowOH
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Message Posted: Jun 29, 2013 9:02:07 AM

My take on this going to neutral on most automatics, benefits me since the ECM is controlling the steady Idle engine speed. The idle load of most torque converters when in drive mode is placed on the engine, that is why one must hold the brake pedal to prevent vehicle creep movement. Whenever the ECM notices that your vehicle hot idle rpms are dropping the correction is made to prevent stalling.

Extra fuel/air balance gets used up to make that correction automatically, and hardly any rpm detection at idle is even noticed, same for Evapo fuel purging, alternator loading, power steering pump loads changing, ETC.

Std. trannies have only a slight benefit clutch system wear/tear, leg stress relief, remember the energy load to your engine at idle changes with what is required by the electrical balance for operating coolant fans, cabin blower speeds, any accessories safety or otherwise is in control at idle by the ECM/EFI on modern vehicles. Savings of fuel can be by driver habits also often minimal but add-up often. HAGDay!
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the1roadhog
Champion Author Atlanta

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Message Posted: Jun 29, 2013 8:50:08 AM

nitzy
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outlaw329
Champion Author Austin

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Message Posted: Jun 29, 2013 12:09:12 AM

On my Wrangler whenever I stop I put it in neutral and coast to a stop, but it is not for saving gas.
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carinthuist
Champion Author San Francisco

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Message Posted: Jun 28, 2013 7:45:25 PM

No
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Houckster
Champion Author Atlanta

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Message Posted: Jun 28, 2013 7:36:00 PM

FORESTGHOST07 writes: Leaving a manual shift car in gear w/ clutch pedal depressed is VERY HARD on the clutch throwout bearing, especially a carbon (not roller bearing) type - premature wear.

I was firmly told that while test driving my 1st car @ 16 ... it stuck w/ me
______
While you were 16? How long ago was that? It's often a mistake to apply to today's cars what might have been true yesterday. Bearings that wear out "prematurely" are bearings that were not properly spec'd for the application.
_____
This question may soon become a moot point for new cars in the near future as a growing percentage of cars will have auto start/stop engines to save fuel and cut emissions.

[Edited by: Houckster at 6/28/2013 7:38:09 PM EST]
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contiki
Champion Author Ontario

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Message Posted: Jun 28, 2013 4:47:19 PM

drive gear........
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PatAZ
Champion Author Tucson

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Message Posted: Jun 28, 2013 11:18:20 AM

I don't if Im driving an automatic and do when driving a manual , not just engaging the clutch.
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CaptainStall
Veteran Author New Brunswick

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Message Posted: Jun 28, 2013 9:57:24 AM

I agree with forestghost07. Leave a motorcycle in gear, but in a car, standing on the clutch while stopped at a light is hard on it (the clutch).

[Edited by: CaptainStall at 6/28/2013 9:58:34 AM EST]
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forestghost07
Champion Author Miami

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Message Posted: Jun 26, 2013 3:29:43 PM

Leaving a manual shift car in gear w/ clutch pedal depressed is VERY HARD on the clutch throwout bearing, especially a carbon (not roller bearing) type - premature wear.

I was firmly told that while test driving my 1st car @ 16 ... it stuck w/ me
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forresj
Champion Author Wilmington

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Message Posted: Jun 26, 2013 11:57:33 AM

Why?

[Edited by: forresj at 6/26/2013 12:03:30 PM EST]
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