How to Save Gas in 10 Seconds… Or Go To Jail
Myth: It takes more gas to turn your car off and on again than to let it idle.
Fact: Idling for more than 10 seconds damages the engine, emits more air pollution, and of course costs more money in the long run than turning the car off and back on again. This is true for all cars built since the 1970s with a catalytic converter.
And yet…
Idling in the developing world
Oddly enough, in the “developing” world, idling your car is not only accepted, it’s a national pastime.
Here in South Korea, a country where oil is at a premium for lack of any domestic reserves, the belief seems to be, “an idle car is a happy car.” Men, especially, have a love affair with the idle car. Perhaps it says, “Hey, ladies… I have money to burn.” Perhaps it’s just a lack of knowledge about car maintenance and air pollution; perhaps it’s a lack of concern.
The problem of idling is even more severe in countries where oil is not at a premium. On my last visit to Venezuela, I spoke with a man named Pedro, who drives charter mini-buses for a living. I asked him why he idles his mini-buses for hours instead of turning off the engine. He smiled proudly. Why shouldn’t he idle his mini-buses? After all, in Venezuela, petrol is cheaper than water.
So here again, idling is a sign of wealth. It’s a case of “waste to show you want not.”
Legal penalties for idling
You may not know it, but your city, county, state, or province may be one of the many with a fine for idling a car.
In the county of Denver, Colorado, idling a car for 10 minutes could land you a fine of no less than $999 and/or imprisonment for one year. A similar penalty of one grand and a year in the slammer applies to anyone in the county of St. Louis, Missouri for idling a car for just 3 minutes. See a list of idling laws in the United States here.
In Canada, of course, fines are less draconian. Idle a car for 3 minutes in Surrey, a city within the Metro Vancouver area in British Columbia, and you’ll get “dinged” $50.
Were these laws news to you? That’s because there’s clearly a disconnect between the laws and their enforcement. Start arresting St. Louis residents for idling and you’ll have a lot of ticked off Missourians. And who really wants a lot of ticked off Missourians?
The answer, as always, is better education about the true costs of idling.
Resources:
Green automotive reading: Gas 2.0
Idling Myths and Facts | Lowering Emissions and Particulates
Turn Off Your Engine! | Environmental Defense Fund
2008 Idle Laws by State | Scribd
In Utah it is a fine of $750 for leaving an unattended car idling.
The problem is there isn’t a single cop that enforces these rules. There are also laws about fishing from horseback. Do you think any cop is going to really give you a ticket for fishing while riding your horse?
Electric cars don’t idle! One more battery breakthrough and we won’t have the idle problem anymore!
What are you talking about man? Leaving your car idling for 5 mins or less burns a lot less gas than turning it off and then on. It requires a lot of fuel to start the engine than to just run it.
In Switzerland only the first three cars in line may idle at traffic lights - other cars must switch off. I also know of complaints from neighbours for idling while clearing snow in the morning..
Hi Joe,
I’m happy to see your comment with some discussion. I’d be very interested to see any articles that support the idea that leaving your car on for five minute uses less gas than turning it off and on.
All of the sources I have tell me that with modern cars, the tipping point for efficiency is 10 seconds. If you’re waiting longer than 10 seconds, it’s more gas friendly to turn the engine off and back on. For instance, please see the links included in the Resources section of this post, right above the comments.
Gavin, I am afraid that Joe is correct. Turning a fuel injected electronic ignition controled vehicle off and then back on forces unignited fuel in vaporived form out the exhaust upon start up. Not a lot but if you were commuting in a metro area you would be dumping a significant amount each trip. I have 15 years experience in the gas and diesel marine engines most of which are based on automotive platforms. Huge a tree and let it idle… more damage is done to the engine with short duration runs. There is almost no research on just how much fuel is dumped upon each start up… but you could calculate how many rpms are turned before the engine starts… and then figure out the number of ignitions should have accured… based on the volume of fuel dispenced on each pulse of the injectors this could be multipled by those cycles before the engine comes to life… pretty simple calculation… a 5.0 liter V8 would dump and estimated .2 gal of fuel with just 5 stop and starts… that just cost $.75 more per day and excessive wear on the engine further shortening the life of the vehicle… if you want to jump on someone case… it should be that of longhaul trucking idling overnight at truck stops… or rail ways that leave their locomotives idling for hours on end… or the public transit buses how clain to be eco friendly… implying that the emmisiions have been reduced… but the reduction is so small and only repeatable in a lab and not real world conditions… sort of like the Prius which claims 50+ MPG but only achieves upper 30s sometimes low 40s in the REAL world…
J Rittenhouse,
Thanks for contributing your experience and knowledge. I’ll continue to read up on more of the details. Interesting that everything I’ve found has given 10 seconds as a rule of thumb (even Car Talk, if I remember correctly) and that legally in lots of places, cars aren’t supposed to idle for more than 3-5 minutes. Definitely a subject worth more checking in to.
Thanks again!
In terms of idling time…
Back in the late 70’s and early 80’s there was talk about all the idling time for the diesels and the huge expenditure of fuel while drivers were letting their trucks idle.
There was a product that came out called an “idle timer”.
It limited a truck’s idling time to 5 minutes, this allowed the engine to go thru a cooling off period and then shut down. It saved countless gallons of diesel fuel.
Here is what I am doing …
4 our future, I am starting my own business promoting and distributing a tested, proven product that saves .35 per gallon, lowers emissions and increases performance.
It works so well, one can also switch from using premium fuel to using regular fuel, that is an additional .10 - .30 per gallon savings on top of the increased MPG savings.
The bottom line: 98-99% of the vehicles using my product will receive a savings of $2.00 - $3.00 for each $1.00 of my product they use.
I am looking to expand this business, and need a few serious people to join me.
If you know of someone who wants to own their own business, promoting a one of a kind product that is
new to the USA and Canada, then contact me.
Timing is critical in my opinion, 4 our future.
Go to my website,
click on “Join Free NOW” to lock in your spot.
Then do your homework, watch our movie, read about our just completed 2 year study on a California government fleet, and make up your mind if this business is for you.
No Cost..No Obligation.
Can you make money with a product that costs $20.00
and gives savings of $40.00 - $60.00?
Serious? Call me with your questions.
My phone number is listed on my website, (about me button).
http://www.MaxMyMileage.com