Which uses less gas?

[umairejaz]

I know the difference is insignificant but which uses less gas….going downhill in neutral or going down hill in gear?

[Echonova]

Accelerating down the hill and coasting up the other side.

[DVSRX-7]

Neutral wins!

[Miss.Kayla]

lol why did you vote gear?

[punkr6]

neutral, lower rpm's= lower fuel consumption....

[98blackcivic]

just buy a couple horses and a carriage and you wont have to worry about gass

[87 Turbo II]

In gear. The modern ECU's cut fuel completely when an engine is decelerating, but to hold idle, it will require fuel. Carbureted cars will and early fuel injection systems might fare better in neutral.

EDIT: wow, I thought everyone knew this when gas was reaching $4.50 a gal, it was all over most of the fuel saving tip lists and mentioned on Top gear and everything. You guys are stupid. Just because your intuition says lower RPM will ALWAYS use less gas, you allow yourself to give false information on a subject where you don't know the answer.

[tnomud]

Even under deceleration, most modern cars engines/trans still drag. It's called compression braking. This dragging will cause more fuel consumption than idling in neutral.

IE: Gravity is using its mystical powers to turn:

a.) 4 wheels, a trans, and an engine with multiple pistons and rotating mass
or....
b.) 4 wheels, a trans...................

[87 Turbo II]

Even under deceleration, most modern cars engines/trans still drag. It's called compression braking. This dragging will cause more fuel consumption than idling in neutral.

IE: Gravity is using its mystical powers to turn:

a.) 4 wheels, a trans, and an engine with multiple pistons and rotating mass
or....
b.) 4 wheels, a trans...................

the dragging will just scrub off speed, but if you coasting down to a stop sign or light, then you were going to be stopped anyway, but if the hill continues upward after it is at the lowest level, then the shed speed may cause you to burn more fuel on the way up, but depending on the grade of the downward hill, you're probably getting better fuel cut from decel than the drag from speed preservation. There are always a million "if"s and loopholes fro MPG.

[DVSRX-7]

lol why did you vote gear?

shhhhhhh, no one has to know, but seriously can someone test this shit out? i don't think Neutral does shit as apposed to being in a gear..

[DVSRX-7]

the dragging will just scrub off speed, but if you coasting down to a stop sign or light, then you were going to be stopped anyway, but if the hill continues upward after it is at the lowest level, then the shed speed may cause you to burn more fuel on the way up, but depending on the grade of the downward hill, you're probably getting better fuel cut from decel than the drag from speed preservation. There are always a million "if"s and loopholes FOR MPG.

fixed :blah:

[87 Turbo II]

fixed :blah:

naw man, I meant fro

http://3.bp.blogspot.com/_D6ZlOTd4Fok/SmtcSLihrkI/AAAAAAAAAA4/H0p0T5nMlqs/s320/afro-bush.jpg
The popular afro hairstyle creates excessive drag which will lower your MPG when used in convertibles or targa tops.

[umairejaz]

lol why did you vote gear?

Because it is the right answer.

[DVSRX-7]

naw man, I meant fro

http://3.bp.blogspot.com/_D6ZlOTd4Fok/SmtcSLihrkI/AAAAAAAAAA4/H0p0T5nMlqs/s320/afro-bush.jpg
The popular afro hairstyle creates excessive drag which will lower your MPG when used in convertibles or targa tops.

ooooooooooooooooooooooooooh frooooo

[87 Turbo II]

haha I'm playin' I meant for

[teh_mugen18]

gear... since the motor leans itself out under those high-vac situations, and when you're in neutral, the AFR's are normal.. lean = less gas. lol.

[Got Milk?]

lololololol at some of the comments in here. lolololol

[DirtyMechanic]

neutral, lower rpm's= lower fuel consumption.... no true.

i know at idle @ 640rpm i have a 3.2ms injector duration. i also know from redline to just about idle in gear off throttle i have roughly a .2-.4ms injector duration so even at 2000-3000rpm (55mph-80mph), highway cruising speeds.

so even if im at 3000rpm the which is going to be 3 times the .2-4ms injector pulse duration at 1000rpms the amount of fuel is going to be .6-1.2ms of the injector being open vs the 3.2-3.4ms of idle injector being open for the same amount of time. get it? hopefully because if works out in my head.


lololololol at some of the comments in here. lolololol
well what is your opinion... can we laugh at yours too.?

[DVSRX-7]

haha I'm playin' I meant for

ddddrrrrrrrrrrrrrrrrrr

[Miss.Kayla]

shhhhhhh, no one has to know, but seriously can someone test this shit out? i don't think Neutral does shit as apposed to being in a gear..

LOL

[Miss.Kayla]

I still think it neutral. either way it still feels better when u put it in neutral
and coast.

[DVSRX-7]

I still think it neutral. either way it still feels better when u put it in neutral
and coast.


yes it does! & my wife asked if you know a lot about cars? :thinking:

[DVSRX-7]

I still think it neutral. either way it still feels better when u put it in neutral
and coast.

oh yea she said nice doggy :nautjerk:

[tnomud]

It's all about mass being turned period. If it's in gear, you are still turning a crankshaft, pistons, cams, and vac/comp. Idling a car still operates injectors at some duty cycle. The engine is still sucking in more air than idle and putting exhaust out. The ECU sees it as "more than idle" and corrects with some (albeit minimal) adjustment over idle.

[tnomud]

yes it does! & my wife asked if you know a lot about cars? :thinking:


man, givin it to the wife hard tonight huh?? (ref: 53 chev post) :D

[DVSRX-7]

man, givin it to the wife hard tonight huh?? (ref: 53 chev post) :D

lol yea she's for sale man.. give me the car for her even trade. :goodjob:

[buffdaddy18]

in gear. your car doesn't use gas when you are in gear and engine braking.

[Miss.Kayla]

yes it does! & my wife asked if you know a lot about cars? :thinking:

um i know my fair share. im not gonna say yes and brag bcus
that always bites people in the ass. lol my dad was a mechanic my
whole life, owned his own shop and what not.


and tell her thank you :) hes my baby boy. (literally hes only 17 months)

[GTScoob]

How the hell is neutral winning the poll?

When engine braking your car uses no gas, when idling it uses a little gas.

[japan4racing]

i cant believe nuetral is winning this poll.....gear under deceleration wins this hands down....anyone that does not believe needs to get a wideband and watch on decel and at idle.

[TheProfiteer]

fuel delivery is almost fully dependent on the degree of throttle position, especially in fuel injected cars. In Neutral your car is electronically programed to provide a specific amount of fuel to keep the car in an idle state, when in gear the ECU of the vehicle is programed to provide a specific amount of fuel depending on how open or closed the throttle is. Thats why you notice that if you gas a car in neutral that your RPMs will dip a bit before returning its programed IDLE RPM.

You will actually get better gas millage in a lower gear at lower speeds than you will at a higher gear, it varies car per car, but for optimum MPG the RPM position should almost always bet just slightly bellow the RPM of where the torque peaks. Because at that position, the force required to keep the car moving in relation to the resistance applied by the transmission will require the throttle to be open much less then it would at a higher gear but lower RPM. This is true for at or around the peak of the torque curve, because after that more force is required to maintain the higher RPMs

For example, traveling 35mph in 4th gear vs 5th. Say your Honda Civic's torque peaks at 3800-4200RPM, in 4th at 35MPH you will be pushing around 3200-3500 RPM, while in 5th gear you will be pushing more like 2600-2800RPM. To keep your car consistently at 35mph requires X amount of force to the wheel. ( I dont know the specific formula for calculating for perpetual velocity) X force to the wheel is achieved by calculating the force produced by the engine, and applied to the resistance of the given gear (weight plays a roll as well, but then you have to factor in inertia and friction). In order for an engine to produce more force it must burn more fuel, so the force necessary to keep the car moving at 35mph at 3500RMP will be less than the force required at 2800RMP (in respect to the torque curve), because it will require the throttle be to open at lesser degree.

Just look at it this way, if you are in 5th gear going 20MPH, and you mash the gas all the way down, even though you car is not accelerating as fast as it would going from 1st-5th, you are still dumping relatively the same amount of gas in to the engine. (especially true for cars with Carbs, as been said modern injected cars have dynamic ECUs, which will actually limit the amount of gas being injected as to not flood the engine)

[dallasb84]

how come skateboard wasnt an option

[umairejaz]

^lol

[Jecht]

In gear. The modern ECU's cut fuel completely when an engine is decelerating, but to hold idle, it will require fuel. Carbureted cars will and early fuel injection systems might fare better in neutral.

EDIT: wow, I thought everyone knew this when gas was reaching $4.50 a gal, it was all over most of the fuel saving tip lists and mentioned on Top gear and everything. You guys are stupid. Just because your intuition says lower RPM will ALWAYS use less gas, you allow yourself to give false information on a subject where you don't know the answer.

:goodjob:


Neutral in my Beetle all the time, its going to get gas regardless.