When stopping at a light....

[bentjazz]

Is it true that when you stop at a light and shift into neutral, you save gas? I read this somewhere, and have been doing it. Just curious to get some feedback on this from those in the know. Thanks....

[caineroad]

it saves about 15 cents from a full tank of gas.

i always do it because i am too lazy to step on the brake, but not for fuel economy.

[bronsin]

Originally Posted by bentjazz

Is it true that when you stop at a light and shift into neutral, you save gas? I read this somewhere, and have been doing it. Just curious to get some feedback on this from those in the know. Thanks....

No and its not true when you take your foot off the gas while moving the FI system shuts off the flow of gas to the engine either. The engine idles when you do that and if the flow of gas was cut off it couldnt.

The thing on the Prius that shuts the engine off at a light and turns it back on again when you press the gas pedal doesnt save any gas either because it takes extra gas to start the engine.

What you CAN do is make a lot of money inventing something in your head that does that and people will believe it.

[nookandcrannycar]

Originally Posted by bronsin

No and its not true when you take your foot off the gas while moving the FI system shuts off the flow of gas to the engine either. The engine idles when you do that and if the flow of gas was cut off it couldnt.

The thing on the Prius that shuts the engine off at a light and turns it back on again when you press the gas pedal doesnt save any gas either because it takes extra gas to start the engine.

What you CAN do is make a lot of money inventing something in your head that does that and people will believe it.

.....isn't there some old saying about the funniest thing (in this case your last sentence) being the truth?

[bairjo]

Originally Posted by bentjazz

Is it true that when you stop at a light and shift into neutral, you save gas?

I never put my Yaris in neutral. My wife will confirm...I have plenty of gas.

[craigq]

When stopped our GLI's fuel economy readout switches from "litres per hundred KM" to "litres per hour". The LPH reading is lower when in neutral (~1.0 LPH) than when the transmission is left in gear (~1.2 LPH) at red lights. I don't see why the Yaris would be different. Is it worth it to keep switching from "D" to "N" and back again at every red light? Not for me...

[Strider]

I do, habit from the days of driving a manual. I like not having to keep hard or sometimes any, pressure on the brake. Never thought it would make a difference in fuel economy.

[nookandcrannycar]

Originally Posted by bronsin

No and its not true when you take your foot off the gas while moving the FI system shuts off the flow of gas to the engine either. The engine idles when you do that and if the flow of gas was cut off it couldnt.

The thing on the Prius that shuts the engine off at a light and turns it back on again when you press the gas pedal doesnt save any gas either because it takes extra gas to start the engine.

What you CAN do is make a lot of money inventing something in your head that does that and people will believe it.

One thing that I read long before this post (but forgot to include on my previous reply) is that either on some old thread here or one on a hypermiling site, the consensus was that if the engine is able to be off for more than 30 seconds at a light one is saving gas because an engine restarting uses the level of gas that 30 seconds of idling does.

[Eli Lilly]

Originally Posted by bronsin

No and its not true when you take your foot off the gas while moving the FI system shuts off the flow of gas to the engine either. The engine idles when you do that and if the flow of gas was cut off it couldnt.

Sure it does, as do nearly all modern vehicles. It obviously doesn't do it in a way that impacts driveability, but in a closed-throttle condition the injectors are not triggered until the RPMs drop below a certain value.

-E

[MUSKOKA800]

The question may be, do the fuel savings by going to neutral at stops offset the wear and tear to the tranny doing same. Transmissions aren't cheap to repair.

[Deathegg]

Originally Posted by bronsin

The thing on the Prius that shuts the engine off at a light and turns it back on again when you press the gas pedal doesnt save any gas either because it takes extra gas to start the engine.

What you CAN do is make a lot of money inventing something in your head that does that and people will believe it.

It takes very little fuel to restart a hot engine. So if you're sitting at a light longer than say 60 seconds, it does pay in the long run to shut off the engine. The European driving cycles they use to measure fuel economy take stop/start into consideration. It's a proven fuel saver.

Not sure what your last sentence means..... :/

[tk1971]

We're all talking automatics here?

With a manual transmission, even in gear, the clutch is engaged when stopped, so at a light, it's always in neutral.

[nookandcrannycar]

Originally Posted by Deathegg

It takes very little fuel to restart a hot engine. So if you're sitting at a light longer than say 60 seconds, it does pay in the long run to shut off the engine. The European driving cycles they use to measure fuel economy take stop/start into consideration. It's a proven fuel saver.

Not sure what your last sentence means..... :/

Agreed. And 30 seconds, 60 seconds -- doesn't matter which it is as either is a short enough period of time to make turning the engine off at most lights worth it.

Last sentence = a 'Bronsinism' . Bronsin thinks that there are many features/items on new cars (including and possibly especially economy cars) that are unnecessary and that the manufacturers just put them on there for profit reasons (and the inclusion of these items pisses Bronsin off). Others of us agree with him, we just don't 'put as many items on that list' as Bronsin does. Bronsin thinks that the off at stop/on at start function mentioned falls into that category. I'm sure Bronsin will correct me if I'm wrong .

[12 yaris]

I do not stop...

[nookandcrannycar]

Originally Posted by 12 yaris

I do not stop...

l Good point that the rest of us missed (the OP didn't specify a red light)......or are you letting us know just how crazy you are behind the wheel .

[auxmike]

I always slap mine into neutral after many years of 5 speeds. Force of habit. Also, saves wear on the mounts, not having a load while stopped...

[Astroman]

Please post your threads in the proper category. This belongs in the fuel economy section, not the general. I've taken the liberty of moving this into the proper category.

And yes, with the auto, shifting into neutral when stopped drops the load on the engine and reduces the fuel consumption about .03-.05 gallons per hour.

[MadMax]

Originally Posted by nookandcrannycar

Agreed. And 30 seconds, 60 seconds -- doesn't matter which it is as either is a short enough period of time to make turning the engine off at most lights worth it.

Last sentence = a 'Bronsinism' . Bronsin thinks that there are many features/items on new cars (including and possibly especially economy cars) that are unnecessary and that the manufacturers just put them on there for profit reasons (and the inclusion of these items pisses Bronsin off). Others of us agree with him, we just don't 'put as many items on that list' as Bronsin does. Bronsin thinks that the off at stop/on at start function mentioned falls into that category. I'm sure Bronsin will correct me if I'm wrong .

Agreed. Some people always think they are smarter than the hundreds of college-educated engineers Toyota hired to design this vehicle...

Whether it is 30 seconds or 60 worth of fuel to restart, traffic lights generally stay red for several minutes so the savings is definitely there.

And considering most manufacturers are incorporating this feature in their new vehicles, I doubt it's some huge conspiracy to increase profit (which would go to the oil companies so why would automobile builder want it?).