Idling – Frequently Asked Questions

  1. With modern vehicle technology and more fuel-efficient cars‚ why do I have to worry about idling?

    It's true that automakers have significantly reduced the CAC emissions from new vehicles. In fact, as a result of automakers' compliance with government regulations and the introduction of cleaner fuel standards, today's vehicles emit about 99 percent less CAC emissions than vehicles built in the 1970's. But one component in tailpipe emissions is directly impacted by the type and amount of fuel your vehicle uses – carbon dioxide (CO2). This is the principle greenhouse gas linked to climate change. Every litre of gasoline that is burned produces about 2.3 kg of CO2. The bottom line: the more fuel you use‚ the more CO2 you produce. And one easy way to cut fuel consumption is to avoid unnecessary idling. After all‚ it gets you nowhere.

  2. How can burning one litre of gasoline (that weighs about 0.75 kg) produce about 2.3 kg of carbon dioxide (CO2)?

    Most fuels are hydrocarbon-based mixtures rich in both hydrogen and carbon. When burned they undergo a chemical reaction resulting in the release of energy (primarily heat) and combustion by-products. When fuel is burned to operate a vehicle‚ a carbon atom combines with two oxygen atoms from the air to produce a corresponding number of CO2 molecules (the other primary by-product of combustion being H2O – water). Gasoline is rich in carbon; in fact in a litre of gasoline that weighs about 0.75 kg, about 86% of the weight is made up of carbon. That is a lot of CO2 molecules – and is how approximately 2.3 kg of CO2 are produced for each litre of fuel that is burned! If you're a motorist who drives 20,000 km each year‚ you're emitting more than four tonnes of CO2 per year that's about three times the weight of your car!

  3. Does an idling vehicle have an impact on the environment? And, if so, is it better to turn off the engine or continue to idle?

    While reducing unnecessary idling can save a significant amount of fuel and reduce GHG emissions, a running vehicle also releases air quality emissions called criteria air contaminants (CACs). Research that examined the CAC impact of turning the engine off and restarting it versus letting your vehicle idle found that no clear choice emerged as both options produce some CAC emissions. However, the studies clearly showed that there are direct benefits – in the form of fuel savings and reduced GHG emissions – obtained by turning the engine off instead of idling. As such, when considering all of the factors, the studies showed it is better to turn the engine off rather than to let it idle unnecessarily. As a practical guideline, balancing factors such as fuel savings, emissions and component wear, if you're going to be stopped for more than 60 seconds it's best to turn the engine off.

  4. Eliminating unnecessary idling is one of many actions that we can take to help reduce fuel use, greenhouse gas emissions and consequently, slow the rate of climate change. But can climate change affect our health as well as our climate?

    According to both Health Canada and Environment Canada, health will be affected, most directly, through temperature extremes of heat or cold that can potentially affect all segments of the population and are not necessarily restricted to a certain vulnerable group. Climate change will affect human health somewhat less directly by affecting the environment and ecosystems within which we live. As a result of climate change – the impact of air pollution levels could increase, affecting local weather, and thereby local and regional pollution concentrations. Precipitation levels, cloud cover, water vapour levels, wind speed and direction all affect how pollutants are dispersed and at what concentrations. Some scientists have suggested that the formation of smog will increase with mean annual temperature increases as the smog precursors of NOX and VOCs react faster at higher temperatures and create more ground-level ozone. As a result, frequent and severe heat waves could translate into more frequent high-ozone-level days and air pollution advisories.

    Secondly, climate change will affect natural sources of air quality emissions, such as forest fires. Increased drought brought on by climate change could influence the occurrence of forest fires since they usually need dry conditions to start. When forests and other vegetation burn, particulate matter as well as large amounts of carbon monoxide (CO), oxides of nitrogen (NOX) sulphur dioxide (SO2) and volatile organic compounds (VOCs) are released into the air.

    Climate change may also change the distribution and types of airborne allergens, such as pollen. Studies have shown that rising levels of CO2 will bring about an increase in the production of pollen in some plants, producing more allergens and thereby making the situation worse for those people suffering from asthma, emphysema and other respiratory illnesses.

  5. Why did NRCan change the 10-second rule to 60 seconds?

    The change was made to balance factors such as fuel savings, emissions and component wear. From this perspective, 60 seconds is the recommended interval. You'll save money on fuel and that should more than offset any potential increased maintenance costs from any extra wear and tear on your starter or battery. And your vehicle won't produce emissions of carbon dioxide, the principle greenhouse gas contributing to climate change. However, motorists should keep in mind that idling for over 10 seconds still uses more fuel and produces more CO2 than restarting your engine. Our message is:

    If you're going to be stopped for more than 60 seconds – except in traffic – turn the engine off. Unnecessary idling wastes money and fuel, and produces greenhouse gases that contribute to climate change.

  6. What do countries around the world recommend as idling turn-off times for their engines?

    In Europe, the recommended guidelines for turning engines off are 10 seconds in Italy and France, 20 seconds in Austria, 40 seconds in Germany and 60 seconds in the Netherlands. In the United States the Environmental Protection Agency's Smartway and DriveWise programs recommend turning the engine off if you're stopped for more than 30 seconds.

  7. Is it more economical and fuel-efficient to leave my car running for a few minutes than to constantly turn it off and on?

    For the average vehicle with a 3-litre engine, every 10 minutes of idling uses over one-quarter of a litre in wasted fuel – and up to one half of a litre if your vehicle has a 5-litre engine. There's no question about it – unnecessary idling gets you nowhere; instead‚ it wastes money and fuel, and produces greenhouse gases that lead to climate change.

    You may be concerned that turning off and restarting the vehicle to avoid idling will result in higher maintenance costs from extra wear and tear of the starter and battery. Actually, the break-even point to offset any incremental maintenance costs is under 60 seconds. You'll save money on fuel that should more than offset any potential increased maintenance costs. And your vehicle won't produce carbon dioxide emissions, the principle greenhouse gas contributing to climate change. As a guideline, if you're going to stop for 60 seconds or more – except in traffic – turn the engine off.

  8. Is it important to idle my vehicle to warm up the engine?

    Contrary to popular belief, excessive idling is not an effective way to warm up your vehicle, even in cold weather. The best way to warm it up is to drive it. In fact, with today's computer-controlled engines, even on cold winter days no more than two to three minutes of idling is usually enough warm-up time before starting to drive. Please consult your owner's manual or your vehicle service advisor if you would like a recommendation specific to your vehicle or climatic conditions.

  9. Is it important to use a block heater in the winter?

    You can help reduce the impact of cold starts – and reduce idling times – by using a block heater. This device warms the coolant, which in turn warms the engine block and lubricants. The engine will start more easily and reach its proper operating temperature faster. What's more, it won't have to work as hard to pump oil through the block. At -20°C, block heaters can improve overall fuel economy by as much as 10 percent. For a single short trip at -25°C your fuel savings could be in the order of 25 percent.

  10. How much fuel am I wasting‚ and how much CO2 do I produce by idling my vehicle?

    An average vehicle with a 3-litre engine idling for ten minutes burns 300 millilitres (over 1 cup) of fuel and this produces 690 grams of CO2. This may not sound like a lot but remember‚ millions of motorists have fallen into the trap of unnecessary idling. In fact‚ if Canadian drivers of light-duty vehicles avoided unnecessary idling for just three minutes every day of the year, we would collectively save 630 million litres of fuel, worth $630 million (assuming a fuel cost of $1 per litre)! Just as important, over the period of a year, we would prevent 1.4 million tonnes of CO2 from entering the atmosphere. That's the equivalent of taking 320,000 cars off of the road! Clearly, individual actions, when taken by millions of Canadians, can make a difference.

  11. What are the most common reasons for idling?

    Warming up a vehicle in the winter and cooling it down in the summer are the most common reasons given for idling. According to a 1998 Natural Resources Canada study of driving attitudes and behaviourFootnote 1, Canadians also spend a lot of time idling their vehicles while waiting for passengers. We also idle when we run quick errands‚ sit in drive-through lanes, stop to talk to an acquaintance or friend‚ prepare to leave the house‚ wait at railway crossings‚ to park or to get gas‚ – even when waiting in line to get our car washed.

  12. What is the «profile» of the typical idler?

    It's safe to say that most Canadian motorists do some idling. However‚ research shows some interesting trends. For example‚ the amount of idling a driver does tends to increase with the number of people in the household. A driver living with children is more likely to idle than one without children. As well‚ the frequency of idling appears to decrease as a person ages – a retiree is the least likely to idle. A person living in a rural area is more likely to idle than a driver living in an urban centre. Regionally‚ a person in British Columbia is the least likely to idle a vehicle.

  13. What steps can I take to minimize idling?

    It's easy – think about fuel efficiency every time you use a car. Try these simple steps:

    1. If you're going to be stopped for more than 60 seconds‚ turn off the engine.
    2. Drive the vehicle to warm it up‚ rather than idling the engine. (Usually no more than two to three minutes of idling is needed on cold winter days.)
    3. Use a block heater on cold winter days to warm the engine before you start it. Use an automatic timer to turn on the block heater two hours before you plan to start the vehicle.
    4. And finally, use remote car starters wisely to avoid excessively long warm ups.