How much fuel does turning the car on consume?

[psyshack]

In all fairness. Xcel over at cleanmpg just had to replace the starter in his 04 Accord LXE. But his tires are the oem orig. equitment. Im sure he FAS/EOC more than anybody else in North America.

Im sure his restarting just exposed a slightly weak starter in his case. As the mode of failure on a modern starter is stustaned cranking. People that have to crank alot on there cars to get them to start due to poor state of tune or mechanical failuer. go thru a lot of starters.

psy

[trebuchet03]

UPS's policy is to have their drivers shut down their engines on all deliveries.... Even those one package rural deliveries. It doesn't take long to deliver one package

I imagine it must take a couple seconds of sitting at a green light to turn the car back on?

You could imagine that.... But in practice, that's not the case Most of use have well maintained vehicles - so start up is quick. I'm in gear releasing the clutch before the idle normalizes after start - so it's like nothing happened

As for extra wear - I'm personally not worried as I'll only do this on a fully warmed up engine. Assuming your oil is still good (that is, it hasn't sheared) - there should still be an oil film after a minute of wait with your engine off

As others have said - if auto mfr's are spending money to implement this - there a good cost/benefit ratio

[GasSavers_StanleyD]

Originally Posted by veloman

...at idle speed, your engine is barely using any gas, so in effect, that 0 mpg time is 'weighted' very litely.
...

Youre right in saying little gas is used, but NO gas is cheaper and economically better than little gas. On a typical trip lets say you stop for 6 lights for an average of 1 min each (6 minutes makes math easy). Thats about .1hour stopped. If your car idles using a mere .4gph then you have lost .04 gals gas at lights. May not seem like much but even a 25mph car can go over a mile on .04 gals gas. Its enough to make a difference.

Originally Posted by veloman

..
I imagine it must take a couple seconds of sitting at a green light to turn the car back on? It must piss off the poeple behind you...

I rarely turn off engine, but when I do I pay attention to tother light and usuallt start car a second BEFORE light changes. Car should start on one crank which is way less than a sec. Maybe the combo of starting and shifting can take over a sec but if you pay attention I dont see how this is a problem. Impatient people behind you are just releasing their brakes to pull off cause they know the light is changing. You can do the same and start your car before the light changes. I just dont see how this is a problem.

Originally Posted by veloman

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IDK, IMO, EOC just doesn't make a lot of sense to me. What happens when you guys hit an extra red light, effectively negating any savings? ...

Once again, unless you actually wait for light to turn back to green and slowly go through mechanics of restarting car, missing extra lights wont happen too often. Driving slowly WILL make you miss lights here and there, but even with those extra missed lights (which you EOC'd into) you will stil have better mpg than if you drove regular. Look at the sports car that flies off the green light and usually sits at the next green light waiting for you to join him 10 sec later as you EOC into a red light just as its turning green. Im sure that a few times during his trip he actually made the light that you missed. Sure, he'll get where he's going before you but at what cost. A few lights with the engine off wont negate any savings. The idea is to try and time the lights. Your speed has little to do with missing lights. If a light is green 50% of time and 50% red rest of the time then you have 50% chance of waiting unless you play the timimg game. People here prob catch LESS red lights than anyone else. Be that sports car waited at MORE red lights than those here.

Originally Posted by veloman

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If it works out good for you, that's all that matter.

To each his own. I respect other peoples decisions even if I dont agree with them. I actually try to understand their decisions as well. I may actually learn quite a lot. I try to tell myself there are no negative posts. Take into account our comments- I actually appreciate the concerns that you have bought up. If you're happy, then thats all that really matters. Dont do anything uncomfortable.
Excuse me for the extra-long post. Happy driving.
StanleyD

[cfg83]

Hello -

My criteria for engine off at stop lights is :

1 - Warm engine (coolant close to normal 190+ degrees F).
2 - Knowing the timing of the light.
3 - If I'm up close, being able to see the other light change.
4 - If I'm far back, still being able to see my light.
5 - On the flat or very little incline such that parking brake is all I need to stay put during restart.

There are so many different situations. If there is a Semi in front of me, I know I can take advantage of his/her slow start to start my car. I mostly try to start my car within 5 to 10 seconds of being required to move my car. That gives me a buffer for a false start.

CarloSW2

[VetteOwner]

lol ive had to replace the starter on my truck once, common thing to go out. that was around 125 K miles. i turn my engine off if i know its going to be a while (like a train) but other than that its too much effort to save pennies when i can find change in a parking lot that would earn me more...that and i dont run into many stoplights or thier quick changing

[Rick Rae]

Originally Posted by VetteOwner

i turn my engine off if i know its going to be a while (like a train) but other than that its too much effort to save pennies... that and i dont run into many stoplights or thier quick changing

I think you've hit it on the mark there, VetteOwner. We each should do what feels right and works for our individual situations.

You don't hit many stoplights and don't see a point in shutting off the engine when you do. Conversely you obviously do see what a waste idling is, and when you see a situation where killing the engine makes sense to you, it's ignition-off. That's cool.

For me, on a route I run once every week or two there's one ridiculously long and insanely sequenced light. The main East/West thoroughfare gets the green for a while, then it steps through one direction (and its left turn light) enabled at a time. The entire sequence -- which is East/West straight through, West, South, North, East -- takes over two minutes.

My route requires me to make a left turn while East-bound. If I hit that intersection when East/West is green, I turn the engine off as I roll into the left turn lane, because I know I'm going to be sitting there for well over two minutes.

I have one other very long light I kill the engine for if the timing's right. All the others are short enough that I don't feel they're worth the hassle or extra wear and tear. Others here would no doubt shut off for most if not all of the lights. Still others would probably idle through even the Methusela light. To each their own!

StanleyD, great example/explanation of fuel wasted during idle!

Rick

[slurp812]

Originally Posted by omgwtfbyobbq

I've heard the injectors firing at startup is equivalent to ~10-15 seconds of idling, and I'm sure you could answer that definitively w/ some manufacturer specific information. Or someone who has some experience programming ECU memory could probably give you a decent idea of the difference in duty cycle. You can also get a remanufactured starter from most auto repair chains w/ a lifetime warranty for less than $100. Starts will kill a starter slowly, but most of the time they die out from prolonged operation/undervolting based on what I've read.

I believe that that would be for a cold start. I don't think you need all that gas for a warm/hot motor. Thats just my best guess. But started wear would be an issue, especially on a jap car. My 94 honda started was 149$ after exchange!

[Hockey4mnhs]

its all about the timeing. I have my hand on the key and looking at the light. I eather watch the outher direction light for when it turns yellow im on by then. most lights i can time really easy because im usally on the same roads and if im on a new one i make a mentle note that this light will turn green when the left turn arrow turns yellow and so on stuff like that really makes it easy and will give you gains. Its not all about saveing money eather i actually enjoy trying to beat my #s knowing i did everything i could to get a better # instead of when im filling up being like what if i would have shut it down at those three lights. Idk thats just how i am call it anal

[DracoFelis]

Originally Posted by Hockey4mnhs

its all about the timeing. I have my hand on the key and looking at the light. I eather watch the outher direction light for when it turns yellow im on by then.

You are more dedicated than I am. I do turn off the ICE when waiting for trains, but leave the ICE on (although often in Neutral) when at lights.

[VetteOwner]

almost all of our lights are traffic controlled so around me there really isnt a point to turn my engine off, if traffic is backed up square blocks and square side streets are awesome cornners to cut in idling time