Does a car still burn gas while moving with its own momentum?

BrokenVisage

Lifer
Jan 29, 2005
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In other words, you build up speed by stepping on the accelerator, then take your foot off it and you keep moving but gradually slowing down from no acceleration.. does this still burn gas?
 

Savij

Diamond Member
Nov 12, 2001
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It's still running, still using the same amount of gas as it would at idle. The rate of gas consumption is controlled by the accelerator.
 

Hyperlite

Diamond Member
May 25, 2004
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ah but the question is, do you use as much gas compression braking at 2500 rpm as you would maintaining 2500rpm?
 

JulesMaximus

No Lifer
Jul 3, 2003
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Originally posted by: Hyperlite
ah but the question is, do you use as much gas compression braking at 2500 rpm as you would maintaining 2500rpm?

No, you would not.
 

BCYL

Diamond Member
Jun 7, 2000
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Originally posted by: Savij
It's still running, still using the same amount of gas as it would at idle. The rate of gas consumption is controlled by the accelerator.

I beg to differ... If you are off the accelerator, but the car is still running at 2500rpm, how is it going to use the same amount of gas as a car idling at 700rpm?
 

BD2003

Lifer
Oct 9, 1999
16,815
1
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The correct answer would be...as long as your car is in gear and not at idle, youre not using ANY fuel. The transmission is turning the engine...if the injectors kept injecting fuel it wouldnt slow down as fast as it does while still in gear. Might be different for older cars though. Drop it into neutral or on an auto coast for long enough and then it has to pump fuel in to keep it at idle.
 

elnovato

Member
Jul 25, 2004
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Originally posted by: BrokenVisage
In other words, you build up speed by stepping on the accelerator, then take your foot off it and you keep moving but gradually slowing down from no acceleration.. does this still burn gas?

Yes it does...and unless you put it in neutral it's burning more than if it were just idling. Put it in neutral and the rpm's drop down to about idle, you burn less gas and will coast a bit further.

e.n. :)
 
Nov 7, 2000
16,403
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Originally posted by: BD2003
The correct answer would be...as long as your car is in gear and not at idle, youre not using ANY fuel. The transmission is turning the engine...if the injectors kept injecting fuel it wouldnt slow down as fast as it does while still in gear. Might be different for older cars though. Drop it into neutral or on an auto coast for long enough and then it has to pump fuel in to keep it at idle.
So the engine stops firing?

 

Templeton

Senior member
Oct 9, 1999
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I know for my manual car, while in gear with foot off accelerator, all fuel to engine is cut. Don't think this is the case with automatics, not sure if all manual cars operate like this (assume all fairly recent computer controlled ones would)
 

elnovato

Member
Jul 25, 2004
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Originally posted by: BD2003
The correct answer would be...as long as your car is in gear and not at idle, youre not using ANY fuel. The transmission is turning the engine...if the injectors kept injecting fuel it wouldnt slow down as fast as it does while still in gear. Might be different for older cars though. Drop it into neutral or on an auto coast for long enough and then it has to pump fuel in to keep it at idle.

If the transmission is turning the engine, what's turning the transmission?
 

Bullhonkie

Golden Member
Sep 28, 2001
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Originally posted by: elnovato
Originally posted by: BD2003
The correct answer would be...as long as your car is in gear and not at idle, youre not using ANY fuel. The transmission is turning the engine...if the injectors kept injecting fuel it wouldnt slow down as fast as it does while still in gear. Might be different for older cars though. Drop it into neutral or on an auto coast for long enough and then it has to pump fuel in to keep it at idle.

If the transmission is turning the engine, what's turning the transmission?

The wheels.

Edit: Oops got beat to it.
 

DougK62

Diamond Member
Mar 28, 2001
8,035
6
81
Are you guys retarded? If the engine is running then it's using gas. Period. Even your manual trans car coasting in neutral to the stoplight is using gas. Engine running means gas is used.

LOL


 

Juice Box

Diamond Member
Nov 7, 2003
9,615
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if you REALLY want to save gas......when you go to coast in Neutral....shut off the engine....the brakes will still work (on most cars)...then just start'er up at the green
 

Scarpozzi

Lifer
Jun 13, 2000
26,392
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Originally posted by: DougK62
Are you guys retarded? If the engine is running then it's using gas. Period. Even your manual trans car coasting in neutral to the stoplight is using gas. Engine running means gas is used.

LOL
Are you sure?
 

BD2003

Lifer
Oct 9, 1999
16,815
1
81
Originally posted by: DougK62
Are you guys retarded? If the engine is running then it's using gas. Period. Even your manual trans car coasting in neutral to the stoplight is using gas. Engine running means gas is used.

LOL

Ill be as simple and concise as I can possibly be. Youre wrong.
 

FoBoT

No Lifer
Apr 30, 2001
63,084
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81
fobot.com
the engine burns fuel, not the car

if the engine is running/turning with fuel entering the combustion chambers, then it is using fuel
 

DougK62

Diamond Member
Mar 28, 2001
8,035
6
81
Originally posted by: BD2003
Originally posted by: DougK62
Are you guys retarded? If the engine is running then it's using gas. Period. Even your manual trans car coasting in neutral to the stoplight is using gas. Engine running means gas is used.

LOL

Ill be as simple and concise as I can possibly be. Youre wrong.

It doesn't make sense to me that I'm wrong. The whole engine running revolves around the explosions in the cylinders to turn the crank. How can that happen with no fuel?