what's wrong with coasting in neutral?

[uctofeej]

I've been reading some hyper-mile websites to increase the gas mileage for my car. One of the tips is to put a vehicle in neutral and coast to a stop whenever possible. But, my piece o' crap car owner's manual clearly says not to coast in neutral (it's a manual). So, I'm wondering what, if anything, does it hurt to put 'er in neutral and coast?

Glad I don't have to worry about this nonsense on my ultra hi-tech AE.

 

[El Toro]

No engine braking, and no power. Your car's a soap box derby racer in neutral.

 

[charismaticmegafauna]

I've been reading some hyper-mile websites to increase the gas mileage for my car. One of the tips is to put a vehicle in neutral and coast to a stop whenever possible. ... So, I'm wondering what, if anything, does it hurt to put 'er in neutral and coast?

Won't hurt nuttin'...

More 'tips': drive barefoot; unplug one headlight....

Glad I don't have to worry about this nonsense on my ultra hi-tech AE.

You can put your 'AE' in neutral, too -- but, depending on speed, it might be a little 'rough' gettin' thru those lower gears....?

Happy Friday

 

[uctofeej]

Actually, I meant mechanically. I drive an old hyundai and I doubt anyone who rolls up behind me expects it to be moving more than 4mph in any case.

 

[uctofeej]

More 'tips': drive barefoot; unplug one headlight....

Yeah, how many headlights do you think a hyundai has?

 

[k7lvo]

I think you'll find that it's illegal to coast in a lot of places.

(These laws were most likely taking big rigs and hills into consideration when they were written, but, in normal government form, I'll bet they don't specify which vehicles they're aiming at.)

 

[uctofeej]

I think you'll find that it's illegal to coast in a lot of places.
(These laws were most likely taking big rigs and hills into consideration when they were written, but, in normal government form, I'll bet they don't specify which vehicles they're aiming at.)

Jeebus! Too fast, get a ticket. Too slow, get a ticket. I'm stuck in the middle.

 

[Bustanut joker]

Another try fer a dogpile goes down in flames

:jester:

 

[uctofeej]

Another try fer a dogpile goes down in flames
:jester:

Oh, admit it. You've gone dry on a Friday

 

[Bustanut joker]

Ya know seems like I read somewhere- a long time ago when ya used premix, that this was somehow bad for the clutch er sumpin.

????????????????

:jester:

 

[FJRBluesman]

Hyper mile by pushing the car up hill, coasting down hill.

 

[dbvolfan]

I coasted all the time in My '79 Dodge Omni....it was the only way home some times!

All's I know is that it aint good for my Suby tranny to coast in N for extended periods of time...dont know why.

 

[jcyuhn]

Don't believe everything you read. Modern fool injected cars completely shut off fuel flow when coasting, generally above certain speed/RPM conditions. Hence the car burns zero fuel when coasting. If you put it in neutral it burns fuel to maintain idle.

I've met folks who drop their car in and out of gear at highway speeds to "save fuel." And they wonder why they need transmission repairs so soon...

- JimY

 

[wfooshee]

Absolutely nothing wrong mechanically with coasting in neutral. You don't want to tow an automatic in neutral with the engine off and drive wheels turning, but with engine running, coasting is fine.

It's not necessarily more fuel-efficient, though. Electronic fuel injection can consume zero fuel on overrun (throttle closed but still in gear) yet has to feed enough fuel to maintain idle when in neutral. You don't coast as far in gear, though. so where's the trade-off? In your head somewhere, whatever feels best.

Problem with coasting in neutral is reacting to some event where power is required will take that extra second or two to get back into gear.

P.S. I was sick yesterday, missed all the Friday fun. Sorry I'm late to the party.

 

[Philip V]

From my understanding, when a car is in nuetral the transmission is no longer pumping fluid, however since the vehicle is still moving you still have parts friction, therefore unnecessary wear to the parts. This is what I was taught as a kid, not sure if it is correct on all vehicles.

 

[Checkswrecks]

We've got a 2003 Caravan and a 2005 Escape that we've tried coasting and it's increased the mileage in each. Not doing anything extreme like turning off the ignition, just coasting when possible. Too soon to be exact, but I'm estimating 5-10% better mileage.

 

[Kaelaria]

On a manual transmission car, there is nothing mechanically wrong with coasting in neutral. What you don't want to do, and may be the intent of what you read - is coast long periods of time with the clutch disengaged (or sit for long periods of time at a light, etc.). The throwout bearing will wear prematurely if you use hold the clutch too much.

 

[FJRBluesman]

In an automatic transmission you have what's called a "torque converter". It has lots-O-tranny fluid in it. It transitions power from the engine to the transmission. If your engine speed is near idle and your tranny is at 65mph coasting down a nice grade, not sure it'll get the proper fluid to all the right parts. On a continual basis it could be an issue. Ask a tranny or car guy. Also engine braking is good. coasting you could be a runaway vehicle so to speak, less control.

I know on dry sump motorcycles it's real bad. The engine oil pump circulates the oil. If the engine is idling, and the tranny is again at much higher speeds, you're starving your transmission for oil. Towing a dry sump bike with the motor off will get you in trouble even quicker as the oil isn't circulating at all.

 

[wfooshee]

From my understanding, when a car is in nuetral the transmission is no longer pumping fluid, however since the vehicle is still moving you still have parts friction, therefore unnecessary wear to the parts. This is what I was taught as a kid, not sure if it is correct on all vehicles.

If the engine is off, then the automatric tranny is not pumping, that's why you don't hook a strap to it and tow it across town. In neutral, the car can be moved, but without hydraulic pressure you're tearing up the guts. Manual tranny lubes by splash of the gears in the case, any motion equals good oil. Coasting in neutral in an automatic with the engine running is OK, for the short-term times being discussed.