Coasting VS Driving Down Hills

With the high prices of gas lately (you have to get a loan to fill up)
I've gotten into the habit of sometimes coasting down long hills in
neutral. I only do this when I can go the speed limit via this method,
and traffic is light. I was wondering the opinion the masses has on
this. Does idling vs driving down hills save you gas, and is it enough
to even bother with? I should say that I drive an 18 wheeler and
coasting down hills is absolutely verboten for obvious reasons, but you
can stop a car a lot faster (especially one with 4 wheel disk brakes).
Is it worth it? I would say in drive, the engine slows while going down
a hill but not as much as idling. So, I guess what I'm asking is am I
wrong for doing this and is it worth it?
Be nice now.....

trotzo wrote:
> With the high prices of gas lately (you have to get a loan to fill up)
> I've gotten into the habit of sometimes coasting down long hills in
> neutral. I only do this when I can go the speed limit via this method,
> and traffic is light. I was wondering the opinion the masses has on
> this. Does idling vs driving down hills save you gas, and is it enough
> to even bother with? I should say that I drive an 18 wheeler and
> coasting down hills is absolutely verboten for obvious reasons, but you
> can stop a car a lot faster (especially one with 4 wheel disk brakes).
> Is it worth it? I would say in drive, the engine slows while going down
> a hill but not as much as idling. So, I guess what I'm asking is am I
> wrong for doing this and is it worth it?
> Be nice now.....
>

ISTR that free-wheeling used to be illegal in IL. Is it still? In other
states?

I tried to look it up in the online MA Driver's License Manual, but that
has been so dumbed-down that I can't tell; I can't tell the difference
between the illegal acts and the ill-advised. Arrrgh.
--
Cheers, Bob

I also figured that the money I'll save in gas I'll make up for in
brake pads....

Bob Willard wrote:
> trotzo wrote:
> > With the high prices of gas lately (you have to get a loan to fill up)
> > I've gotten into the habit of sometimes coasting down long hills in
> > neutral. I only do this when I can go the speed limit via this method,
> > and traffic is light. I was wondering the opinion the masses has on
> > this. Does idling vs driving down hills save you gas, and is it enough
> > to even bother with? I should say that I drive an 18 wheeler and
> > coasting down hills is absolutely verboten for obvious reasons, but you
> > can stop a car a lot faster (especially one with 4 wheel disk brakes).
> > Is it worth it? I would say in drive, the engine slows while going down
> > a hill but not as much as idling. So, I guess what I'm asking is am I
> > wrong for doing this and is it worth it?
> > Be nice now.....
> >
>
> ISTR that free-wheeling used to be illegal in IL. Is it still? In other
> states?
>
> I tried to look it up in the online MA Driver's License Manual, but that
> has been so dumbed-down that I can't tell; I can't tell the difference
> between the illegal acts and the ill-advised. Arrrgh.
> --
> Cheers, Bob

"trotzo" > wrote in message
> With the high prices of gas lately (you have to get a loan to fill up)
> I've gotten into the habit of sometimes coasting down long hills in
> neutral. I only do this when I can go the speed limit via this method,
> and traffic is light. I was wondering the opinion the masses has on
> this. Does idling vs driving down hills save you gas, and is it enough
> to even bother with? I should say that I drive an 18 wheeler and
> coasting down hills is absolutely verboten for obvious reasons, but you
> can stop a car a lot faster (especially one with 4 wheel disk brakes).
> Is it worth it? I would say in drive, the engine slows while going down
> a hill but not as much as idling. So, I guess what I'm asking is am I
> wrong for doing this and is it worth it?
> Be nice now.....
>

In California, it's illegal to do that. Having said that, I used to work
with a guy that would shut his engine off while going down hills, in order
to save gas. He was a real character.

Bob

Back in the day....
My grandfather did that, he would just pop his old car into neutral and
leave it running so the brakes and steering still worked.
He claimed it saved him a lot of gas.

I have noticed since I got my Libby that the little mpg indicator has a big
change when I let off the accelerator or decelerate, from 17mpg under
throttle to as high as 49
Soooooooooooo since we ALL know how bugus THAT is
I would guess that you may save a little, BUT
The only way to know for sure it so test the theory on the same course with
and without your foot on the pedal.

--
Kate
2O|||||||O5 Liberty


"Bob" > wrote in message
.net...
:
: "trotzo" > wrote in message
: > With the high prices of gas lately (you have to get a loan to fill up)
: > I've gotten into the habit of sometimes coasting down long hills in
: > neutral. I only do this when I can go the speed limit via this method,
: > and traffic is light. I was wondering the opinion the masses has on
: > this. Does idling vs driving down hills save you gas, and is it enough
: > to even bother with? I should say that I drive an 18 wheeler and
: > coasting down hills is absolutely verboten for obvious reasons, but you
: > can stop a car a lot faster (especially one with 4 wheel disk brakes).
: > Is it worth it? I would say in drive, the engine slows while going down
: > a hill but not as much as idling. So, I guess what I'm asking is am I
: > wrong for doing this and is it worth it?
: > Be nice now.....
: >
:
: In California, it's illegal to do that. Having said that, I used to work
: with a guy that would shut his engine off while going down hills, in order
: to save gas. He was a real character.
:
: Bob
:
:

On 18 Sep 2005 10:34:32 -0700, "trotzo" > wrote:

>With the high prices of gas lately (you have to get a loan to fill up)
>I've gotten into the habit of sometimes coasting down long hills in
>neutral. I only do this when I can go the speed limit via this method,
>and traffic is light. I was wondering the opinion the masses has on
>this. Does idling vs driving down hills save you gas, and is it enough
>to even bother with? I should say that I drive an 18 wheeler and
>coasting down hills is absolutely verboten for obvious reasons, but you
>can stop a car a lot faster (especially one with 4 wheel disk brakes).
>Is it worth it? I would say in drive, the engine slows while going down
>a hill but not as much as idling. So, I guess what I'm asking is am I
>wrong for doing this and is it worth it?
>Be nice now.....

I think it is risky. Suppose the engine stalls ? bye bye powerbrakes.

I don't think it's worth the small amount you save.

RT wrote:
> On 18 Sep 2005 10:34:32 -0700, "trotzo" > wrote:
>
>
>>With the high prices of gas lately (you have to get a loan to fill up)
>>I've gotten into the habit of sometimes coasting down long hills in
>>neutral. I only do this when I can go the speed limit via this method,
>>and traffic is light. I was wondering the opinion the masses has on
>>this. Does idling vs driving down hills save you gas, and is it enough
>>to even bother with? I should say that I drive an 18 wheeler and
>>coasting down hills is absolutely verboten for obvious reasons, but you
>>can stop a car a lot faster (especially one with 4 wheel disk brakes).
>>Is it worth it? I would say in drive, the engine slows while going down
>>a hill but not as much as idling. So, I guess what I'm asking is am I
>>wrong for doing this and is it worth it?
>>Be nice now.....
>
>
> I think it is risky. Suppose the engine stalls ? bye bye powerbrakes.
>


Then you let off the clutch again. Duhhh.


--

"Gullible is a misdemeanor - stupid is a felony...
clueless gets you committed..." - JG

coasting down long hills in
neutral. "WindsorFox[SS]" > wrote in message
news:0goXe.12393$nq.10664@lakeread05...
> RT wrote:
>> On 18 Sep 2005 10:34:32 -0700, "trotzo" > wrote:
>>
>>
>>>With the high prices of gas lately (you have to get a loan to fill up)
>>>I've gotten into the habit of sometimes coasting down long hills in
>>>neutral. I only do this when I can go the speed limit via this method,
>>>and traffic is light. I was wondering the opinion the masses has on
>>>this. Does idling vs driving down hills save you gas, and is it enough
>>>to even bother with? I should say that I drive an 18 wheeler and
>>>coasting down hills is absolutely verboten for obvious reasons, but you
>>>can stop a car a lot faster (especially one with 4 wheel disk brakes).
>>>Is it worth it? I would say in drive, the engine slows while going down
>>>a hill but not as much as idling. So, I guess what I'm asking is am I
>>>wrong for doing this and is it worth it?
>>>Be nice now.....
>>
>>
>> I think it is risky. Suppose the engine stalls ? bye bye powerbrakes.
>>
>
>
> Then you let off the clutch again. Duhhh.
>
>
> --
>
> "Gullible is a misdemeanor - stupid is a felony...
> clueless gets you committed..." - JG

"Kate" > wrote in message
. net...
> Back in the day....
> My grandfather did that, he would just pop his old car into neutral and
> leave it running so the brakes and steering still worked.
> He claimed it saved him a lot of gas.
>
> I have noticed since I got my Libby that the little mpg indicator has a
big
> change when I let off the accelerator or decelerate, from 17mpg under
> throttle to as high as 49
> Soooooooooooo since we ALL know how bugus THAT is
> I would guess that you may save a little, BUT
> The only way to know for sure it so test the theory on the same course
with
> and without your foot on the pedal.
>
> --
I've noticed that the fuel consumption (l/100km) indicator on my Durango
will often go to zero on long down hill grades. My guess is that the
computer is regulating fuel flow to maintain speed. Therefore with there
being no fuel flow necessary to maintain speed the flow is closed to a
trickle and possibly shut off.

--
Richard

'94 GT 'vert
Under Drive Pulleys
Transgo HD2 Reprogramming Kit
High Stall Torque Converter
4:10 Gears
Gripp Sub Frame Connectors (welded)
FRPP Aluminum Drive shaft
FRPP M5400-A Suspension
Laser Red
..

I think it depends on your system. I recall when cruising in a 56
Pontiac 'vert, with a spark plug wired to the exhaust pipe, that you
shut off the engine and coasted and then fired it up again and hit a
toggle for the plug. You got a huge flame from the raw exhaust gases
which were still being pumped through the system while coasting.

Newer systems which are computer controlled may prevent that.

That said, and aside from being illegal in a lot of places, as I
recall you waste the most fuel when starting up. The second biggest
waste of fuel is idling at traffic lights, in traffic (hello, LA),
etc. Would not coasting be akin to idling, and restarting as bad as
restarting if you were to have the engine shut off or die? So, could
it be that, unless a computer is doing something to prevent waste,
you'd be wasting more fuel trying to trick the system than just
driving normally?

And what of any added wear and tear on parts?

I don't know. I'm not an engineer. But it seems like you are not
really saving anything. That it just might be an urban legend that you
do.

On 18 Sep 2005 10:34:32 -0700, "trotzo" > wrote:

>With the high prices of gas lately (you have to get a loan to fill up)
>I've gotten into the habit of sometimes coasting down long hills in
>neutral. I only do this when I can go the speed limit via this method,
>and traffic is light. I was wondering the opinion the masses has on
>this. Does idling vs driving down hills save you gas, and is it enough
>to even bother with? I should say that I drive an 18 wheeler and
>coasting down hills is absolutely verboten for obvious reasons, but you
>can stop a car a lot faster (especially one with 4 wheel disk brakes).
>Is it worth it? I would say in drive, the engine slows while going down
>a hill but not as much as idling. So, I guess what I'm asking is am I
>wrong for doing this and is it worth it?
>Be nice now.....

Spike
1965 Ford Mustang fastback 2+2 A Code 289 C4 Trac-Lok
Vintage Burgundy w/Black Standard Interior; Vintage 40
16" rims w/BF Goodrich Comp T/A gForce Radial
225/50ZR16 KDWS skins; surround sound audio-video.

Gad what fools these morons be....
Children are obscene but should not be heard
Give me a peperoni pizza... or give me a calzone!