Gas Savings Idea, but will it hurt the transmission????

[jjhtca]

I heard on a radio advertisement yesterday about a car manufacturer (I cannot remember which one) is going to have one of their models shift to neutral while the car is at a stop light or idling for a period of time. This is in an effort to save fuel, the idea is that a car uses less fuel in neutral than in drive. I do not have the specifics on how long before it shifts into neutral or how it knows to shift back into drive once the light turns green.

This lead me to think, rather than waiting on technology, I can do this myself. I can shift my truck into neutral at a red light and then back into drive when the light turns green.

Better yet, I can shift to neutral when approaching a red light (before I am completely stopped) and coast in.

What about if I am going down hill...I can shift into neutral and coast down hill and then shift back into drive once I am at the bottom of the hill (while still moving).

All of these thoughts have led me to this question...what affect (if any) will this have on my transmission? Will this really be a noticeable fuel savings?

[2008_CrewMax]

you'll prob get an extra 1 mile out of every tank

[ponyuk]

Some interesting idea's, I am not sure how safe they are. If people are thinking like this at $5 a gallon, what would you all do if faced with $19 a gallon -

A Devon petrol station has been charging ... £9 (approx $19) a gallon
BBC NEWS | England | Devon | Fuel £1.99 a litre as tanks dry

now dropped:

BBC NEWS | England | Devon | Petrol station drops £1.99 charge

Originally Posted by jjhtca

I heard on a radio advertisement yesterday about a car manufacturer (I cannot remember which one) is going to have one of their models shift to neutral while the car is at a stop light or idling for a period of time. This is in an effort to save fuel, the idea is that a car uses less fuel in neutral than in drive. I do not have the specifics on how long before it shifts into neutral or how it knows to shift back into drive once the light turns green.

This lead me to think, rather than waiting on technology, I can do this myself. I can shift my truck into neutral at a red light and then back into drive when the light turns green.

Better yet, I can shift to neutral when approaching a red light (before I am completely stopped) and coast in.

What about if I am going down hill...I can shift into neutral and coast down hill and then shift back into drive once I am at the bottom of the hill (while still moving).

All of these thoughts have led me to this question...what affect (if any) will this have on my transmission? Will this really be a noticeable fuel savings?

[2008_CrewMax]

Originally Posted by ponyuk

Some interesting idea's, I am not sure how safe they are. If people are thinking like this at $5 a gallon, what would you all do if faced with $19 a gallon -

A Devon petrol station has been charging ... £9 (approx $19) a gallon
BBC NEWS | England | Devon | Fuel £1.99 a litre as tanks dry

now dropped:

BBC NEWS | England | Devon | Petrol station drops £1.99 charge

£9 is approx $17.5 i believe

(still outrageous)

[08CMAX]

I dont think it will save anything at stop. When I shift from neutral to drive my RPMs go down..meaning less squirts of fuel for combustion to keep the engine running.

[2008_CrewMax]

Originally Posted by 08CMAX

I dont think it will save anything at stop. When I shift from neutral to drive my RPMs go down..meaning less squirts of fuel for combustion to keep the engine running.

that seems to only happen when the engine is cold

mine seems to drop when i shift into neutral (or stay about even) when the engine is warm

i agree that it wont save anything though

[ponyuk]

You are right, it looks like the dollar recovered a bit recently. Just before Christmas, a £ bought you a little over 2$.

Originally Posted by 2008_CrewMax

£9 is approx $17.5 i believe

(still outrageous)

[adazzleman]

I imagine it wouldn't have any ill effects on the transmission....but I am not an expert. If you think about it, it is almost like doing a double clutch in a manual transmission. You put it in first throw it in neutral then put it into 2nd, than throw it in N again, and so on. That doesn't hurt the car. I don't see why an automatic would be effected by putting it in neutral when stopping or going down hill. I would agree with everyone else that it wouldn't make that much of a difference, and the irritation wouldn't be worth it. The best way to save gas is to drive slower. I used to drive 85 on the interstate. I started driving 75 now. It makes a difference. If prices keep going up I am going to put it on 65. If you really think about it, you don't get there a whole lot later.

[ponyuk]

Could brake pressure drop if braking hard (say going down a steep hill) when the engine was only idling?

[Ironman02]

Originally Posted by adazzleman

I imagine it wouldn't have any ill effects on the transmission....but I am not an expert. If you think about it, it is almost like doing a double clutch in a manual transmission. You put it in first throw it in neutral then put it into 2nd, than throw it in N again, and so on. That doesn't hurt the car. I don't see why an automatic would be effected by putting it in neutral when stopping or going down hill. I would agree with everyone else that it wouldn't make that much of a difference, and the irritation wouldn't be worth it. The best way to save gas is to drive slower. I used to drive 85 on the interstate. I started driving 75 now. It makes a difference. If prices keep going up I am going to put it on 65. If you really think about it, you don't get there a whole lot later.

Not that I’m a professional, but the manual transmission has less moving parts in it apposed to the tons of little balls, springs, and the stall converter that of the automatic transmission; which is why I think you can beat on a (stock) manual more so than an automatic. I could be wrong though?

[goneballistic]

Originally Posted by ponyuk

Could brake pressure drop if braking hard (say going down a steep hill) when the engine was only idling?

Vacuum off an engine intake manifold is rather high at an idle. When I was a kid we had a '61 Mercury with vacuum powered windshield wipers. They would slow down to a craw under acceleration.

[Rollin Thunder]

You Could Probably Get A Better Result By Adding 10 Psi More Into Your Tires...run Them To The Max Rating....so Its A Little Rough !

[kit]

Not that it's too much work, but it's prolly not worth the trouble of having to keep shifting. I doubt you'll see a difference that would justify it.

[jjhtca]

Thanks for all the replies. If shifting to neutral will not have much affect on fuel savings, then it kind of makes me wonder what the car manufacturer is thinkning who came up with this idea. Maybe it is just an illusion to sell more cars (make people think they are saving gas)

I will keep an ear out for that commercial again to see if I can pick up on who is doing it. I do remember that the car was not due out for a couple of years.

Gas at $4.00 a gallon is not hurting me that much. Heck, gas for the boat hurts more than the truck. But $19.00 a gallon...now I understand why all the European cars look like smart cars.

http://misslissa.files.wordpress.com...pg?w=300&h=187

[Toxarch]

Every little gimmick means another future sale when gas prices keep rising.

When I was a kid, my dad used to throw the car in neutral, cut off the engine and coast down straight hills. When he got to the bottom, he'd start the engine, put it back in gear and keep driving. He did that for a long time until one day we were driving to Minnesota and the car wouldn't start somewhere in the middle of Iowa... in the winter... with his wife and 3 young boys in the car. He had to hitch hike back to the last town to call a wrecker. Car needed a new starter so we had to wait there while a new one was put in the Oldsmobile. I think that was the last time he killed the engine to coast down hills to save gas. Now he tries to take the inside lane on curves. I keep trying to tell him that wears on his tires faster.