View Full Version : Is it bad to coast in neutral....
bentjazz
04-22-2012, 12:09 PM
While on the highway, I coast while driving towards the off ramp when I go to the gym. it's all down hill and my Ecometer has hit as high as 329mpg. I do it to amuse myself and to save gas, but I was wondering if it's bad for the tranny to coast in neutral?
Thanks.
WeeYari
04-22-2012, 12:13 PM
No it is not bad for the tranny. If you really want to have fun with the ecometer, try coasting while in gear. If you can hold the engine to above 1100rpm (I think that is the number) without pressing on the gas petal, DFCO kicks in and no fuel is being used. Once engine idle drops below 1100, fuel is being fed to the engine.
Beat us all to it lol ^
OP- there is a sticky on this
http://www.yarisworld.com/forums/showthread.php?t=4248
jayeh
04-22-2012, 04:44 PM
While on the highway, I coast while driving towards the off ramp when I go to the gym. it's all down hill and my Ecometer has hit as high as 329mpg. I do it to amuse myself and to save gas, but I was wondering if it's bad for the tranny to coast in neutral?
Thanks.
Well, if you coast in gear you aren't using an fuel but in neutral you are using fuel to run the engine. The difference is marginal.
You're also putting additional wear on the brakes too since you are losing any compression braking effect.
But its your car so go nuts!
ilikerice
04-22-2012, 05:38 PM
OH GEZUS, NOT THIS THREAD AGAIN!
NOOOOOO:hitcomputer:
bentjazz
04-23-2012, 09:40 AM
Thanks, guys. I hit 349mpg this morning. Oh yeah....
Well, if you coast in gear you aren't using an fuel but in neutral you are using fuel to run the engine. The difference is marginal.
You're also putting additional wear on the brakes too since you are losing any compression braking effect.
But its your car so go nuts!
what you wrote is wrong. Please read more on the fe forums, the information to correct you is all there. Thank You.
jayeh
04-23-2012, 01:20 PM
what you wrote is wrong. Please read more on the fe forums, the information to correct you is all there. Thank You.
Huh?
Even the sticky thread in the FE forum says to leave it in gear? :iono:
Sparcoboy
04-23-2012, 02:08 PM
Huh?
Even the sticky thread in the FE forum says to leave it in gear? :iono:
You are correct, why? is wrong :D
brg88tx
04-24-2012, 11:33 AM
last standard i had was a 4 cylinder nissan frontier truck and i used to coast in neutral a lot. i had to replace the throwout bearing at just over 100,000 miles and i always wondered if it was due to coasting in neutral.
Sparcoboy
04-24-2012, 01:16 PM
What does a throwout bearing have to do with coasting in neutral?
It only wears when your pushing the clutch pedal.
:rolleyes:You are correct, why? is wrong :D
here we go again. There are only two instances where leaving the car in gear will get you better gas mileage, if you are going down a steep enough hill that the car keeps the acceleration anyways, or if you are slowing down to a stop anyways. On a flat road leaving the car in gear will get worse mileage than putting it in neutral will, because you will have to hit the gas pedal more with the engine sucking the energy out of your forward momentum.
In reality a combination of both is the best to get the best gas mileage, depending on the situation you are in and the traffic, etc.
Sparcoboy
04-24-2012, 06:18 PM
Coasting will never save you gas if you don't intend to stop or at least slow down. The best way to get from a to b is at a constant speed. Just coasting and then accelerate to your previous speed is useless
Coasting will never save you gas if you don't intend to stop or at least slow down. The best way to get from a to b is at a constant speed. Just coasting and then accelerate to your previous speed is useless
This is totally false, as countless thousands of hyper milers have proven beyond a shadow of a doubt.
:rolleyes:There are only two instances where leaving the car in gear will get you better gas mileage, if you are going down a steep enough hill that the car keeps the acceleration anyways, or if you are slowing down to a stop anyways.
this is a pretty narrow minded way to look at this, and may encourage people to look at this the wrong way
let me re-word what you're saying:
always leave the car in the most optimal gear, except for when you're just about to go below 1000PRPM in first and stop.
doing this, will ensure you will have the best MPG possible, as being in neutral never helps your MPG
daf62757
05-01-2012, 02:05 PM
I am not questioning the DFCO issue but while I was on a long downhill glide, the gas gas dropped a level. I was in Drive and my foot of the gas pedal, so if it doesn't use any gas, why did the gas level drop? Couldn't have been the angle of the road or car on the road because that was a constant. There has to be some gas being used for the gauge to register a drop in fuel.
Sparcoboy
05-01-2012, 02:37 PM
because your gas tank ain't level no more the sensor may measure a lower level.
I am not questioning the DFCO issue but while I was on a long downhill glide, the gas gas dropped a level. I was in Drive and my foot of the gas pedal, so if it doesn't use any gas, why did the gas level drop? Couldn't have been the angle of the road or car on the road because that was a constant. There has to be some gas being used for the gauge to register a drop in fuel.
i wouldn't take that to be accurate, for a whole slew of reasons. mostly, among which, that it isn't super accurate in terms of time. so, i wouldn't consider that
Betrivent
05-01-2012, 10:39 PM
The fact that is was not a level surface makes this observation completely subjective and inaccurate.
The fact that is was not a level surface makes this observation completely subjective and inaccurate.
even if it was level, i still wouldn't consider it
bentjazz
05-31-2012, 03:56 PM
I've been coasting a lot in neutral lately, and just filled up today. It was the second best fe reading I've received to date on a tank of gas. I think why? is onto something, in that it depends on the situation. Sometimes it's best to go with DFCO, but that's not always possible and in those instances neutral fits the bill just fine. I'll keep experimenting.....
I've noticed that the engine breaking in the yaris is actually a lot more noticeable than in my cavalier. neutral coasting in my cavalier actually yielded me worse mileage than leaving it in gear.
also, pulse and glide is a proven technique. many guys on gassavers have done it (and still do). there are also guys that EOC (engine off coast) which is the most fuel efficient way but questionable when it comes to transmission wear (that is yet another argument to be had).
many guys on gassavers are getting 30+% more than the EPA numbers for their cars and some of the real crazies have exceeded that by leaps and bounds.
caineroad
05-31-2012, 06:37 PM
is not bad but don't put back to drive while car is moving
is not bad but don't put back to drive while car is moving
yes because shifting is such a horrible thing to do... Oh wait, that is what the car is designed to do.
new-yaris-owner
06-28-2012, 07:14 PM
I only put it from Drive to Neutral when I see that I will need to stop at a red light.
I instantly see the RPMs going from 2200-2300 to 800... Also easier to brake!
Correct me if I'm wrong to do that way
goliath1812
06-28-2012, 10:04 PM
I only put it from Drive to Neutral when I see that I will need to stop at a red light.
I instantly see the RPMs going from 2200-2300 to 800... Also easier to brake!
Correct me if I'm wrong to do that way
if you need to stop, or slow down...leave it in drive and take your foot off the gas pedal.
xhifer
06-28-2012, 10:22 PM
I've always thought neutral uses more gas.
new-yaris-owner
07-01-2012, 03:30 PM
Is it hard on the tranny if I put from Neutral to Drive while moving like 20mph ?
tooter
07-01-2012, 06:27 PM
I've always thought neutral uses more gas.
I feel safer coasting with the car in gear. :smile:
And coasting in gear takes advantage of the deceleration fuel cut off feature where no fuel is being metered to the engine while coasting in gear as long as the engine rpms remain above idle. Whereas when idling in neutral, fuel is being fed to the engine.
cali yaris
07-01-2012, 08:14 PM
^ That is correct. Because of DFCO, you'll get better mileage leaving it in gear.
if you need to stop, or slow down...leave it in drive and take your foot off the gas pedal.
coming to a stop is one the highlights of using DFCO. Slowing down, it depends. If you need to brake, leave it in DFCO, if you can just coast, neutral could be better, unless you are going down a steep enough hill that DFCO does not slow you down at all.
Is it hard on the tranny if I put from Neutral to Drive while moving like 20mph ?
no, it is designed to do that. You have to go through neutral every time you shift.
yarista
07-04-2012, 10:21 AM
Ok- I see alot of chitter chatter here and a lack of basic automotive technology. Every carmaker that I have ever encountered has placed restrictions on towing an automatic car with the drive wheels spinning. The reason is that auto trans have an oil pump inside that force oils certain bearings. When the auto trans is in neutral, the pump is inop, so no oil to those bearings. If u put ur auto trans in neutral and coast, some bearings are not getting the oil that they should. Now, will short, no oil to certain bearings, coasts cause damage? I don't know and we don't try to findout with my auto trans Yaris. As for a manual trans, the gears spin when the front wheels move and the parts are splash lubricated. Hence, you don't find restrictions for towing manual trans cars with the drive wheels spinning and the trans in neutral. So, I do coast my manual trans Yaris in neutral. Ergo, I cannot believe it good practice to coast an auto trans Yaris in neutral.
bentjazz
07-06-2012, 02:19 AM
Okay, that does it. No more coasting in neutral for me. The extra 2mpg I get isn't worth possibly screwing up my transmission.....
rningonfumes
07-06-2012, 03:50 AM
Actually, you never stated which transmission you had. Everyone else debated and compared the pros and cons of manual/Auto.
Ok- I see alot of chitter chatter here and a lack of basic automotive technology. Every carmaker that I have ever encountered has placed restrictions on towing an automatic car with the drive wheels spinning. The reason is that auto trans have an oil pump inside that force oils certain bearings. When the auto trans is in neutral, the pump is inop, so no oil to those bearings. If u put ur auto trans in neutral and coast, some bearings are not getting the oil that they should. Now, will short, no oil to certain bearings, coasts cause damage? I don't know and we don't try to findout with my auto trans Yaris. As for a manual trans, the gears spin when the front wheels move and the parts are splash lubricated. Hence, you don't find restrictions for towing manual trans cars with the drive wheels spinning and the trans in neutral. So, I do coast my manual trans Yaris in neutral. Ergo, I cannot believe it good practice to coast an auto trans Yaris in neutral.
I agree with some of that, with a major caveat. Today's oil is so viscous it sticks to everything in an engine, and a minute or two of neutral coasting is not enough to remove the oil.http://www.youtube.com/watch?v=pcYBgod7L_k This is a test of people running a car with no oil for 51 minutes, plus 6 minutes of very high revs. Other types of tests have been done that have concluded the same basic thing.
Not to mention towing is very different from coasting. Towing assumes the vehicle will never be on at all. Coasting does have the vehicle on and everything running, and if the transmission requires said oils, why would the car not add them just for being into neutral? That would make no sense to me.
And while most hyper milers have manual cars, not all of them do. I have not seen any of them blow a transmission from coasting.
mr_miles
07-07-2012, 02:57 AM
i had to edit this. couldn't resist.
http://img.photobucket.com/albums/v232/vash_the_stamepede/Serps.jpg
tooter
07-07-2012, 03:18 AM
That's hilarious! :laugh:
Red Horse
07-08-2012, 02:57 PM
2008 yaris sedan 150,000 miles automatic. Im always coasting in neutral (everyday, pretending my car is a stick) and never had any problem or any maintenace on the tranny. This is inovation welcome to the future, no more wear and tear.
tooter
07-08-2012, 07:43 PM
2008 yaris sedan 150,000 miles automatic. Im always coasting in neutral (everyday, pretending my car is a stick) and never had any problem or any maintenace on the tranny. This is inovation welcome to the future, no more wear and tear.
I wouldn't think that would cause a problem because as long as your engine is even just idling, it's still circulating the transmission fluid. Coasting in neutral with the engine off would be a different matter.
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