Saving Gas

[Anonymous-0]

Does it do any good to put auto trans in nuteral at a light? Or shut it off at a long four way light? I had a hill comming home from work where I could coast almost 3 mi another 1 mi. 4 mi. x 5 days is 20 miles a week. This was at midnight and no other cars were on the road. Another question on coasting does it hurt a auto trans to coast with the motor off a few miles. Yes I know not to shut the key completely off, I found out the hard way on my chevy chevette, almost ran the thing in a ditch with the stearing wheel locked. Stan

 

[Drew]

With the engine off, you have no power steering and no power brakes. With the engine off in neutral, you arent circulating ATF to cool/lube moving parts.

I say its a bad idea all around; and the savings, if any, will be nil.

 

[Steve in IL]

Chief - It does help to shift into neutral for stop lights. Allison & Cat torque converter automatics have a "auto neutral" feature to help save fuel. I also shut my engine off at known long lights. And coast "til the cows come home. I think that this stuff has helped me get about 17mpg average (including around town) with my "05 Suburban.

 

[Alan Golden]

A vehicle will use more fuel while it is starting that it will just idling. I can't remember the stats, but I would think you'd end up burning more fuel from all the shutting down and restarting.

 

[RobMD]

I just put the car in neutral going down hills and my stick shift truck in neutral going down hills too. I never shut anything off, if a KIDDDD runs out in front of you, you don't have a chance in heil.

 

[old]

Putting on in netrul many save gas but its also not legal and if something happens you could get in big trouble

 

[Dan-IA]

I've always put it in neutral, I just didn't see the sense of unnecessarily lugging an idle-rpmed gas engine.

I will shut off a car if I get stuck in long lines like rush hour traffic or exiting a parking ramp after a rock concert or leaving the July 4th fireworks display, but anything under about 2 minutes stopped and I let it idle. That catches almost all traffic lights around here.

Dont shut off your engine at a traffic light if you cant see the light for the traffic crossing in front of you. When their light goes yellow is when you should be starting your car to not impede traffic.

 

[noncompos]

Recent web comments are that carb engines use more restarting at a normal stoplight than is used idling, but that electronics would save gas...but you have the extra starter and ring gear wear, both expensive...
On the AT's and coasting with engine idling, in neutral, my understanding is it depends on the design of the AT; some aren't hurt, some can or will be; we need a good AT person to answer this one, or we could look at our owners manuals to see if it's mentioned...

 

[Anonymous-0]

I dont remember the Nuetral selection on the column being mentioned as illegal to use in My particular copy of the student handbook when I studied for my license.The transmission wont be hurt at all coasting as long as the motor is running

 

[ericlb]

i dont know about the car drivers licence book, but in the truck book it is defenatly mentioned and it says ' the vehicle cannot be allowed to coast in netural for any distance longer than the vehicle', it does not say anything about idleing in netural at a traffic lite, i dont see why that would be a problem, as for shutting the engine off and restarting it at a traffic lite, if its a gas engine, your starting system better be in top shape,if its a a turbocharged diesel thats about the hardest thing you can do to it,if you think fuel is expensive, just wait untill you pay for a shelled out turbo and whatever else it tore up when it went

 

[MarkB_MI]

I know that coasting in neutral is illegal in Colorado. It's illegal in most, if not all, mountainous states. This is one of those offenses that is essentially unenforceable, but if you have an accident and the cop thinks you were coasting he'll write you up for it.

 

[Anonymous-0]

If an idling engine stalls while coasting,power steering and brakes are gone.Try shutting off the ignition in a big parking lot if you need a demonstration.

 

[tlak]

They make cars that shutoff at certain times so I figured it can't be all bad. I started shutting off when I usually left running, like checking the mail.

 

[RodinNS]

I spose you might save a bit by putting the transmission in neutral. I wouldn't shut it off though. How much gas are you going to save to pay for the extra starter use? Probably not that much. I was at a light yesterday and while I was pulling away I heard a woman starting her VW jetta TDI up as I was pulling away. When she has an engine ingest a turbo from that stunt, she'll learn why you don't shut turbo diesel's off at a light, but ofcourse some people will never learn...
I think I'd refrain from the coasting too. Considering that it's illegal in most places, it might not be a good idea anyway...

Rod

 

[Richard G.]

I guess none of you remember the little Nash car that put itself in neutral when going down hill. A spinster teacher at my high school had one forever.

 

[jose bagge]

A lot of those old Saabs like Walt drives had a freewheel mode so when you went down a hill they would freewheel and coast

 

[Revredneck]

If your vehicle is new enough to have electronic fuel injection you don't gain anything by putting it in neutral and coasting. The computer automatically shuts the fuel off and gives the engine only enough to keep running. In fact, coasting in neutral will actually set a trouble code and turn on the "check engine" light.
Good Luck and God Bless.

 

[HENRY E NC]

I think coasting in gear is the smart thing to do because on my instant mileage indicator the mileage goes way up. I am not sure about most cars but mu old Lincoln goes into free wheeling when coasting. Here in the mountains I can coast about half way to town indicating 99 mpg but coming home I have to climb back up at 16 or 17 MPG. I also do average about 22.5 MPG and when on a long trip can average about 26 MPG. My Jeep Grand Cherokee all wheel drive will indicate 45 MPG down hill and only get 17MPG over all. No free wheeling on it. Nuff said Henry NC

 

[old]

Yep its not legal. But also just because you did not see that in the book not know is your problem not the cops if and when something would happen. I know for a fact its in the CDL manual

 

[dbernie]

A little insight on coasting (or towing) in neutral, engine off, with many automatics--as was previously stated, it won't lube the trans, and it can burn it up if done long enough--the front pump doesn't turn when the engine is not turning, so no fluid circulation.
However, some automatic transmissions (not many) are designed with a rear pump that rotates as the driveshaft rotates, which will keep the fluid pumping. I'm sure there's other exceptions, as well.

One would have to check data on the particular transmission to find out, as was previously stated.

 

[Brian Jasper co. Ia]

Being a transmission tech at a GM dealer, I can say all lubrication stops when the engine stops. I would not coast for any length of time with the engine off. The hybrid C/K 1500 from a couple years ago is a start stop mainly in town. They use an electric pump to keep the trans pressurized when the engine is not operating for lubrication and to have instant operation when the brake is released and accelerator is pushed.
The rear pump in an automatic trans was eliminated in the 60's. A rear pump trans can be push started, all others not.

 

[Brian Jasper co. Ia]

I also meant to add fuel injected GM and Fords go into fuel cutoff mode if you coast down hill long enough without touching the brake. I'm going to say thats very likely true with just about everybody else.

 

[buickanddeere]

Think of the millions of gallons of gasoline saved daily if. People would park their vehicles and walk their fat *sses into the restaurant instead of idling in the drivethrough.
And how many impatient people have you seen idling next to the gas pumps. Waiting to drive in rather than either backing up to take another lane. Or backing up to an available pump.

 

[Anonymous-0]

Ive noticed a somewhat good savings by using cruise control on exactly 55mph on highway,however, Im the only one at that speed.Everyone is passing me.Around town I find myself speeding down hills,I just hate to put the brakes on free momentum.

 

[John M]

And the thousands of vehicles towed behind big fancy motorhomes all bad trannys? Just how long does it take to wear these out if thats the case?

 

[Anonymous-0]

No lubricating oil is being pumped thru the trans when it is in neutral so it will save a little gas. But with no lubrication you could eventually damage the trans. When stopped put it in "Park" instead. I would not "coast" with an automatic. Buy a manual if you want to"coast".