Save Gas By Reducing Car Idling

Tips on How to Eliminate your Idling

Technology and modern innovations often catch up and meet society’s demands, but our habits sometimes keep us behind the times. Case in point: idling. I grew up in cold climates and have spent many of my adult years surviving snowy winters. I dutifully climbed into the car every winter morning, 10 minutes early to ‘warm up the engine’. I was also told that turning the engine on and off was bad for the starter and the engine, so I, being the good girl, stayed in the car and kept my engine humming.

Last week when I began researching ways to save gas and reduce exhaust admissions, I discovered that I’ve been mistaken for years. These rules made sense decades ago but became obsolete with innovations like the catalytic converter and major improvements in the design and manufacturing of batteries and starters. Idling in today’s passenger cars wastes gas, creates unnecessary pollution, and may add to the wear and tear of your car.


Vehicle idling and the impact on gas mileage

There really is no benefit to running your engine when the car is not moving. It does take a small increase in gas to start the car, but after 10 seconds you are wasting more gas by idling then if you turned it off and then restarted when you were ready to move. Remember, idling achieves 0 miles per gallon.

I believed in all of the following myths, but not any more.

  • Idling Myth – You have to warm up the engine or you’ll cause damage. This might have been true in the past, but not any more. Even in cold weather, today’s cars only need about 30 seconds before their ready to go. You need to warm up everything in cold climates and that includes the transmission, tires, wheel bearings and moving parts. So start driving and get moving: you’ll heat up the entire car faster and prevent needless greenhouse gas emissions from being produced.
  • Idling Myth – You save gas and money by idling instead of turning the car off and on. Remember the 10 second rule. After 10 seconds of idling you will be using more gas idling then if you turned the engine off. If you are just stopping for about 10 seconds, leave the engine on, if you are stopping for a longer period, turn off the motor. 30 minutes of idling burns 1/10 to 3/10 of a gallon of gas. [1]
  • Idling Myth – You will hurt your starter and engine by frequent starts.Just the opposite is often true. Excessive vehicle idling can cause damage to different engine components including cylinders, spark plugs, and exhaust system. Idling your car also increases condensation which can corrode the exhaust system and shorten its effectiveness.[2]  The starter is made to be turned on and off thousands of times and modern systems are durable. (If you have an automatic starter-reduce the weight of your key chain and you’ll extend the starter’s life.)

Many state and national governments are launching anti-idling programs, some are emphasizing education and awareness, others are legislating strict fines for parked idling cars. It was estimated in an April 2009 EcoDrivingUSA report that $28 million dollars are wasted by idling in New York City. This is based on a $2.00 per average gasoline cost and $2.50 per gallon price for diesel.[3] New York joined many other cities in enacting touch anti idling laws with fines as high as $2000.00. Denver, known for it’s cold weather has a anti-idling law on their books that makes it a violation to idle for more then 5 minutes even in cold weather.[4]  A recent Japanese study showed an increased awareness in the wastefulness of idling, although only 4% of survey participants would turn their engines off instead of idling while driving (in heavy congestion or long traffic lights.)

I know old habits die hard, so here are a few more reasons to convince you turn off the engine and stop idling.

  • Save money on gas - The amount varies on the type of car and amount of idling you regularly do, but avoiding 10 minutes of idling your car a day will save you many hundreds of dollars over the life of your car.
  • Reduce air pollution - Idling unnecessarily adds carbon monoxide, nitrogen oxides and other gases into the air. This is an easy way to reduce air pollution.
  • Prevent theft - Indianapolis Police Department reported that 25% of stolen cars were taken when the keys were in the ignition and the engine was running.[5]
  • Save your engine - Today’s engines are made to move the car, not to idle. Engine parts can be damaged by extended vehicle idling.
  • Prevent accidents -  Cars idling are sometimes accidentally engaged and cause accidents. Think about the times you’ve waited in car pool lines or in a parking lot with the motor running. Accidents are common in these situations.

After I did the research, I decided to keep a log to see how often I park with the engine running. I was surprised. I’ve gotten into many very bad habits and keeping a journal helped me discover how often I idle while parked. Here’s what I found.

  • Idling in my driveway -  The first thing I did when I got into my car was turn on the engine, then I buckle my seatbelt, adjust the mirror, check directions, wait for passengers, etc. I often spent 1 to 3 minutes idling in my driveway. I’m now reversing my habits and only turning on the engine after everything is in place.
  • Idling in the drive-through - I caught myself leaving the engine on at the bank drive-through. I was parked for almost 3 minutes.
  • Waiting - Dropping off and picking up passengers always took more then 30 seconds. Now I turn off the engine as soon as I get to my destination and stop my vehicle from idling.
  • Talking on the Cell Phone - I pull over when I talk on my cell, but I was not in the habit of turning off the engine during short calls. Now I park, turn off the engine, and then make the call.
  • Speaking with friends in the car – Something was wired in my brain to keep the engine going when I’m parked with friends in my car. I realized I can still talk with them without idling the car. If it’s getting too cold or hot, we can go inside.

The result of my journal showed me that I left my car idling up to 30 minutes on busy in-town driving days. Why not check out your own idling habits, by keeping a journal to discover how much you’ll save when you turn off the engine.



1 Should I shut off the motor when I'm idling my car. California Energy Commission. Retrieved June 4, 2010.

2 Idling myths and facts. Leap. Retrieved June 4, 2010.

3 Case Study: EcoDriving - American Programs and Results December 2009. Retrieved June 4, 2010.

4 Buy and drive smart. US Environmental Protection Agency. Retrieved June 5, 2010.

5 Smart schools don't idle. Improving Kids' Environment. Retrieved June 5, 2010.

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