# How much gas would I use if I let my car idle all day? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [December 21, 2004, 7:21pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020 "2004-12-21T19:21:09Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Winston\_Smith](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@Winston\_Smith](https://boards.straightdope.com/u/Winston_Smith)\ **Post date:** [December 21, 2004, 7:21pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/1 "2004-12-21T19:21:09Z")
I work in a secure office park, and I can use my spare key to lock the car, so I’m not concerned about theft (plus I have insurance). I want my car to be nice and warm when I leave the office in the evening, or if I want to run out and get a cafe-mocha-double-expresso. I asked around the office about fuel consumption, and the only source I’d consider even remotely authoritative said a gallon an hour. That sounds like a lot - but he’s no Celil Adams. I was thinking more like a gallon all day. By the way, I drive a new Honda Accord Sedan with a 4-cyl motor (for your calculations). Winston ---
**Author:** ![Earthworm\_Jim](https://avatars.discourse-cdn.com/v4/letter/e/f07891/32.png) [@Earthworm\_Jim](https://boards.straightdope.com/u/Earthworm_Jim)\ **Post date:** [December 21, 2004, 7:31pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/2 "2004-12-21T19:31:40Z")
Not exactly a ‘controlled experiment’, but my brother let his (IIRC) '95 Camaro idle from about 10PM - 8AM one night accidentally. He said it used about 1/2 the tank. He could have been exaggerating, though. ---
**Author:** ![Metacom](https://avatars.discourse-cdn.com/v4/letter/m/ecae2f/32.png) [@Metacom](https://boards.straightdope.com/u/Metacom)\ **Post date:** [December 21, 2004, 7:57pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/3 "2004-12-21T19:57:28Z")
Buying a remote starter might be a much better option. ---
**Author:** ![Jenaroph](https://avatars.discourse-cdn.com/v4/letter/j/e8c25b/32.png) [@Jenaroph](https://boards.straightdope.com/u/Jenaroph)\ **Post date:** [December 21, 2004, 8:05pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/4 "2004-12-21T20:05:31Z")
From [AAA’s site](http://www.csaa.com/global/faqdetail/0,1397,1004010401%257C231,00.html): > [@](#): > > Don’t let your car idle for more than a minute. Idling consumes a half-gallon to a gallon of gas per hour and wastes more gas than restarting the engine. From [about.com](http://financialplan.about.com/cs/cars/a/SaveGas.htm): > [@](#): > > … idling wastes about a quart of gas every 15 minutes. So, from half a gallon to a gallon per hour times 10 hours as **Jim** noted could be anywhere from 5 to 10 gallons. Yeah, that could be half the tank, depending on the car. You want to pay 20 bucks a day in order to have a warm car when you leave work? Don’t do it. ---
**Author:** ![audiobottle](https://avatars.discourse-cdn.com/v4/letter/a/bc8723/32.png) [@audiobottle](https://boards.straightdope.com/u/audiobottle)\ **Post date:** [December 21, 2004, 8:07pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/5 "2004-12-21T20:07:38Z")
[This site](http://www.therecord.com/links/links_04100475540.html) says that idling for more than 10 seconds burns gas twice as fast as an average speed moving vehicle (whatever speed that is). Another [site](http://www.theonlineinvestor.com/nancy.phtml?content=na_beat_gas) says idling uses 1/2 to 1 gallon of gas an hour. I think you’re definitely best off not leaving it idling all day from a cost perspective, to say nothing of the amount of harmful emissions. ---
**Author:** ![Aagramn](https://avatars.discourse-cdn.com/v4/letter/a/e8c25b/32.png) [@Aagramn](https://boards.straightdope.com/u/Aagramn)\ **Post date:** [December 21, 2004, 8:17pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/6 "2004-12-21T20:17:55Z")
This would also reduce the life of the engine very significantly, and could cause your car to fill up with carbon monoxide fumes. ---
**Author:** ![Winston\_Smith](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@Winston\_Smith](https://boards.straightdope.com/u/Winston_Smith)\ **Post date:** [December 21, 2004, 8:23pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/7 "2004-12-21T20:23:36Z")
> [@Aagramn](#): > > This would also reduce the life of the engine very significantly, and could cause your car to fill up with carbon monoxide fumes. Mmmmm… Carbon monoxide ::drool:: ---
**Author:** ![CynicalGabe](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@CynicalGabe](https://boards.straightdope.com/u/CynicalGabe)\ **Post date:** [December 21, 2004, 9:05pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/8 "2004-12-21T21:05:20Z")
I am pretty sure you can go to hell for leaving your car idlnig all day. Just get a remote starter. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [December 21, 2004, 9:10pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/9 "2004-12-21T21:10:22Z")
> [@Jenaroph](#): > > You want to pay 20 bucks a day in order to have a warm car when you leave work? He could pay the $20 and answer his own question. But this isn’t GQ. ---
**Author:** ![UrbanChic](https://avatars.discourse-cdn.com/v4/letter/u/9dc877/32.png) [@UrbanChic](https://boards.straightdope.com/u/UrbanChic)\ **Post date:** [December 21, 2004, 9:46pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/10 "2004-12-21T21:46:07Z")
An idle car is Aaron Neville’s playground. …or something like that. ---
**Author:** ![beltbuckle](https://avatars.discourse-cdn.com/v4/letter/b/3da27b/32.png) [@beltbuckle](https://boards.straightdope.com/u/beltbuckle)\ **Post date:** [December 22, 2004, 4:20am UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/11 "2004-12-22T04:20:36Z")
Look into getting a remote start installed. Besides being a bad idea, it is horrible on your engine to let it idle for long periods of time. The oil presure is at it’s lowest point, the coolant circulation is not as good, etc. It basically puts a lot of unnecessary wear on your engine. So spend that money on a remote start kit, or give the $15 you would spend to have your car idling all day to a co-worker or something. Heck, I will glady start your car for you for $15! ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [December 22, 2004, 6:14am UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/12 "2004-12-22T06:14:53Z")
Every time you let your car idle for hours God kills a kitten. ---
**Author:** ![jackelope](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@jackelope](https://boards.straightdope.com/u/jackelope)\ **Post date:** [December 22, 2004, 6:17am UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/13 "2004-12-22T06:17:18Z")
As described in [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=165733), I locked the keys in my truck with the engine running a few years ago, and it burned slightly under two gallons in about two and a half hours. ---
**Author:** ![Winston\_Smith](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@Winston\_Smith](https://boards.straightdope.com/u/Winston_Smith)\ **Post date:** [December 22, 2004, 2:05pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/14 "2004-12-22T14:05:21Z")
> [@beltbuckle](#): > > Look into getting a remote start installed. Besides being a bad idea, it is horrible on your engine to let it idle for long periods of time. The oil presure is at it’s lowest point, the coolant circulation is not as good, etc. It basically puts a lot of unnecessary wear on your engine. > > So spend that money on a remote start kit, or give the $15 you would spend to have your car idling all day to a co-worker or something. Heck, I will glady start your car for you for $15! This $15 you are proposing: is that a flat fee, or do you mean per ‘incident’? ---
**Author:** ![beltbuckle](https://avatars.discourse-cdn.com/v4/letter/b/3da27b/32.png) [@beltbuckle](https://boards.straightdope.com/u/beltbuckle)\ **Post date:** [December 22, 2004, 4:39pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/15 "2004-12-22T16:39:26Z")
The $15 will cover two starts a day, $4 per additional start. ---
**Author:** ![Winston\_Smith](https://avatars.discourse-cdn.com/v4/letter/w/e95f7d/32.png) [@Winston\_Smith](https://boards.straightdope.com/u/Winston_Smith)\ **Post date:** [December 22, 2004, 4:54pm UTC](https://boards.straightdope.com/t/how-much-gas-would-i-use-if-i-let-my-car-idle-all-day/281020/16 "2004-12-22T16:54:43Z")
> [@beltbuckle](#): > > The $15 will cover two starts a day, $4 per additional start. Have your people call my people. We’ll work something out.