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pattyt
07-22-2008, 11:11 AM
3. Don’t idle – when you let your vehicle idle longer than 10 seconds, you burn more fuel than you would restarting the engine. When you arrive at a major intersection with turning lanes, try turning off your car and restart it right before your light is about to change


Thats on the homepage, and im having a hard time believing thats true. Is this actually proven, because it will save me alot of gas spent while idling if it is.

gretz
07-22-2008, 11:15 AM
:bullshit:

Tik-Tok
07-22-2008, 11:17 AM
I know with carb'd vehicles, it needs to be a 30+ second wait to be worth it, but with the newest fuel injected technology, I can believe it.


Personally I have a whole 5 sets of lights between myself and work (over 20 km), but if a downtowner wants to test this theory, that'd be awesome.

eb0i
07-22-2008, 11:20 AM
Even if it's true I would hate if anyone was doing this. People are so slow to react already to a light, let alone having them turn on their car in anticipation of the light then going. I could see this putting less cars through on a light. Also would it really save that much gas to make it worth the effort, I don't think so.

Brendan_4g63
07-22-2008, 11:20 AM
Another thing I think is bull shit is the fill up in the morning one, when the gas is colder... Its in the ground. Its cold all day long, when you feel the spout when your filling, its cool to the touch.
Don't think 10ft underground changes that much during the day.
Thoughts?

teggypimp95
07-22-2008, 11:22 AM
No to mention thats alot of wear on your starter and such. I would never turn off my car at lights just to save gas.

badatusrnames
07-22-2008, 11:32 AM
Originally posted by eb0i
Even if it's true I would hate if anyone was doing this. People are so slow to react already to a light, let alone having them turn on their car in anticipation of the light then going. I could see this putting less cars through on a light. Also would it really save that much gas to make it worth the effort, I don't think so.

Couldn't agree more. Nothing is more frustrating than when cars simply craaawl of the line. You think that if people were a little more snappy and moved to cruising speed quickly, you'd get twice as many cars through some intersections and ease congestion. Advance turns especially seem to suffer from this. But with people becoming more conscious about conserving fuel, I can only see people moving slower from lights.


Originally posted by Brendan_4g63

Don't think 10ft underground changes that much during the day.
Thoughts?

:werd:

Eleanor
07-22-2008, 11:34 AM
Originally posted by Brendan_4g63
Another thing I think is bull shit is the fill up in the morning one, when the gas is colder... Its in the ground. Its cold all day long, when you feel the spout when your filling, its cool to the touch.
Don't think 10ft underground changes that much during the day.
Thoughts?

AFAIK all volumes at the pump are now corrected to 15C anyway.

dr_jared88
07-22-2008, 11:37 AM
Originally posted by Brendan_4g63
Another thing I think is bull shit is the fill up in the morning one, when the gas is colder... Its in the ground. Its cold all day long, when you feel the spout when your filling, its cool to the touch.
Don't think 10ft underground changes that much during the day.
Thoughts?

I know the pumps I fill at say that they are corrected to 10 degrees Celsius so I don't think it would make a difference.

The Cosworth
07-22-2008, 11:38 AM
Originally posted by Eleanor


AFAIK all volumes at the pump are now corrected to 15C anyway.



Originally posted by dr_jared88


I know the pumps I fill at say that they are corrected to 10 degrees Celsius so I don't think it would make a difference.


I've got a question for you guys. Ok if it is -25 out all they do is heat the line and correct it to 10/15 degrees but if it is 35 degrees outside do they cool the gasoline with AC or something? or is underground temp always lower than 10/15

revelations
07-22-2008, 11:41 AM
In some European locations (switzerland?), its law that all vehicles, except the first 2 in line, at a red light stop their engines. Note that Euro traffic lights turn yellow BEFORE green to let you know its time to let off the clutch.

Commuters driving the same route every day get to know lights pretty well - here is where you can save your engine and gas at the same time - why idle for 90 seconds needlessly when you know how long it takes before you can go ?

Your starter is not that weak. Id rather wear that out than the engine anyway.

The other side of that coin is that you should not do this when the engine is cold as stopping it will slow down the warm up process (should be fine after 5 min of driving anyway).

badatusrnames
07-22-2008, 12:59 PM
Originally posted by revelations
Note that Euro traffic lights turn yellow BEFORE green to let you know its time to let off the clutch.


I like that idea. I remember my Danish neighbour speaking about how in Europe, people seem to move so much more efficiently through lights. Here the light goes red and everyone falls asleep.

benyl
07-22-2008, 01:18 PM
Originally posted by The Cosworth


I've got a question for you guys. Ok if it is -25 out all they do is heat the line and correct it to 10/15 degrees but if it is 35 degrees outside do they cool the gasoline with AC or something? or is underground temp always lower than 10/15

No they don't do that.

You do get more fuel in the winter than in the summer. Gas, unlike water, expands and contracts with temperature variations.

badatusrnames
07-22-2008, 01:27 PM
Originally posted by benyl


No they don't do that.

You do get more fuel in the winter than in the summer. Gas, unlike water, expands and contracts with temperature variations.

Exactly, you get a greater volume of fuel, but the heat content (BTUs, Joules, etc) is that same...

bspot
07-22-2008, 02:20 PM
Originally posted by revelations
In some European locations (switzerland?), its law that all vehicles, except the first 2 in line, at a red light stop their engines. Note that Euro traffic lights turn yellow BEFORE green to let you know its time to let off the clutch.

Commuters driving the same route every day get to know lights pretty well - here is where you can save your engine and gas at the same time - why idle for 90 seconds needlessly when you know how long it takes before you can go ?

Your starter is not that weak. Id rather wear that out than the engine anyway.

The other side of that coin is that you should not do this when the engine is cold as stopping it will slow down the warm up process (should be fine after 5 min of driving anyway).

Yeah, in Switzerland they for sure have this. They even have little signs that show you to turn your engine on when the light goes yellow and red.

It's sweet there, no one runs reds, because the cars coming the other way start going as soon as they get their yellow, so if you didn't stop, you will get t-boned when they come off the line.

Eleanor
07-22-2008, 02:33 PM
Originally posted by The Cosworth
I've got a question for you guys. Ok if it is -25 out all they do is heat the line and correct it to 10/15 degrees but if it is 35 degrees outside do they cool the gasoline with AC or something? or is underground temp always lower than 10/15

No, they don't change the temperature of the gasoline when they give it to you, what they do instead is determine the equivalent amount (mass) of gasoline at 15C (or 10C can't remember, it's usually written on the pump) and charge you for that volume. So, as Benyl mentioned, you get a larger volume of gas in the winter, but the same mass of gas. The density changes with temperature (& pressure too, but that doesn't vary enough to warrant a correction).

Technically they should be charging not per liter, but per gram/kilogram.

tentacles
07-22-2008, 02:46 PM
European Market BMW 1 Series with manual transmissions can shut off the engine as soon as you are stopped and shift into neutral, and restart as soon as you hit the clutch.

Here's a link, I don't know if it works because of all the Flash.

http://www.bmw.co.uk/bmwuk/efficient_dynamics/bc/homepage/0,,___,00.html?bcsource=nationaltop

The Cosworth
07-22-2008, 03:44 PM
Originally posted by Eleanor


No, they don't change the temperature of the gasoline when they give it to you, what they do instead is determine the equivalent amount (mass) of gasoline at 15C (or 10C can't remember, it's usually written on the pump) and charge you for that volume. So, as Benyl mentioned, you get a larger volume of gas in the winter, but the same mass of gas. The density changes with temperature (& pressure too, but that doesn't vary enough to warrant a correction).

Technically they should be charging not per liter, but per gram/kilogram.

oh so they dont actually correct the temperature of the fuel, they just compensate and measure it and charge it as if it were 10/15 degrees?

badatusrnames
07-22-2008, 03:49 PM
Originally posted by The Cosworth


oh so they dont actually correct the temperature of the fuel, they just compensate and measure it and charge it as if it were 10/15 degrees?

Yeah, you're getting the same amount of gasoline (same number of molecules type of thing), just a different volume.

subsin
07-22-2008, 04:10 PM
Originally posted by benyl


No they don't do that.

You do get more fuel in the winter than in the summer. Gas, unlike water, expands and contracts with temperature variations.

plus gas prices are cheaper =] so its a plus plus

badatusrnames
07-22-2008, 04:14 PM
Originally posted by subsin


plus gas prices are cheaper =] so its a plus plus

You don't get it. The volume changes according to temperature, but the actual amount (if you count molecules) of fuel doesn't. Like eleanor said, they should really sell it by weight. You are still buying the same amount of energy.

bart
07-22-2008, 05:57 PM
my car uses 0.5L/hour when idling. small engine gas cars probably aren't much more. so its costing me 75cents for every full hour i'm idling... i would be retarded to shut my car off at red lights.

rmk
07-22-2008, 06:23 PM
turning you car off at lights = cheap

eb0i
07-26-2008, 12:44 AM
I'll try it on my next few tanks of gas to see what happens. I will turn it off while waiting in long drive thru lines as well.

revelations
07-26-2008, 12:51 AM
Originally posted by bart
my car uses 0.5L/hour when idling. small engine gas cars probably aren't much more. so its costing me 75cents for every full hour i'm idling... i would be retarded to shut my car off at red lights.

With numbers like that, no one is going to argue with you.

Diesels are inherently efficient at idle whereas gas engines arent (something about the airflow patterns).... but even at 1L per hour (for eg.) , its not really a huge difference unless you idle a lot.

The question then becomes an envorinmental one... shutting off your engine saves the EARTH :burnout: