Any Big Savings In Coasting In Neutral With Engine On?

[dsq]

Is there any big saving in just throwing the car into N but not turning engine off?
For instance when approaching a red light from a block away i will throw into N and cruise to a slow stop.Or if im going down a steep hill.
I am not crazy about turning engine off with an automatic.

[NeilBlanchard]

Hello,

It is hard to turn off the engine in any car -- steering and braking are very difficult w/o the engine running. So, yes, shifting to neutral saves fuel.

[Johnny Mullet]

I coast as much as possible and where traffic allows. This alone has saved me fuel.

[whokilledthejams]

I coast as much as I possibly can, and it definitely gets me a couple of mpg.

[ankit]

Coasting in gear will probably save fuel. I lost FE when coasting in neutral (automatic trans) because apparently there is a fuel cutoff in my vehicle. It actually burns fuel when in N instead of not burning when coasting in D.

Also, I don't know if going into neutral is too good for your tranny, I made a thread about that and it had mixed answers. http://ecomodder.com/forum/showthrea...anny-1153.html

[adam728]

I think it depends a lot on the car. My Malibu seems to shift back into gear fine even at highway speeds. Also, idle is higher when in gear, ie, in park or neutral the TPS will be 7 clicks open, in gear it will usually stay 10-13 clicks open. Playing around the other day waiting in line at the border crossing I got
Idle, in gear, AC on - 0.51 gph
Idle, in gear, AC off - 0.43 gph
Idle, in neutral, AC on - 0.41 gph
Idle, in neutral, AC off - 0.29 gph

Looking at that tells me there could be some significant fuel savings coasting in neutral, especially with turning off AC.

But like everyone says, every car is different.

[MasterAlex]

I hear yah, I've got a HCH1 and whenever I put it in neutral (it doesn't turn off like the prius does unless you have the break engaged) it maxes out on the millage where when I'm just coasting sometimes it doesn't. It will save gas if you do it at a stop light, and it would be easier on the car as well, right?

[dcb]

Originally Posted by NeilBlanchard

It is hard to turn off the engine in any car

Not really "any" car, manual steering cars don't have any steering issues with the engine off and the reserve brake vacuum is managable, heck I can lock the tires up even when the vacuum is gone. But I also have a parking brake and engine braking (stick shift) if necessary. It really just a matter of practice, in a safe location preferrably.

But even in our power steering saturn, the steering effort isn't unbearable as long as the car is rolling. My wife manages the corners just fine. Though I would like to eventually swap in a manual rack just to save a bit more gas by not constantly running the power steering pump.

It really depends on the driver and car.

[IndyIan]

In my automatic Neon I do alot of coasting with the engine on, on the highway. At 100km/h it coasts in neutral at about 1.7L/100km where if I'm in gear just giving enough gas to counteract engine braking the scangauge reads about 3.5 or 4L/100km. In town I don't bother going into neutral unless I can sneak a glide in. My car doesn't read any different idling in or out of gear.
Going back into gear at 50mph is a bit of a trick, I find if I try to rev match by holding the throttle open the tranny will think about going into second gear for a second, but if I just blip the gas it goes into 3rd(highest gear) and I tickle the gas some more and it locks the converter for the next pulse, shoot up to 100km/h and repeat.
On my last trip home I got 5.4L/100km in an auto Neon so I must've done something right!
Ian

[thebrad]

Not scientific by any means, but according to SGII I get better fuel economy coasting in gear? Possibly a false positive.

http://youtube.com/watch?v=P_en3k_D0c4

I made this video yesterday on the same topic for another forum.