emissions technology and more fuel-efficient cars, why do I have to
worry about a small matter like idling?
It’s true that automakers have succeeded in cleaning up most of the
harmful substances emitted by vehicles. Compared with unregulated
vehicles 30 years ago, today’s new cars generate 98 percent fewer
hydrocarbons, 96 percent less carbon monoxide and 90 percent fewer
nitrous oxides. But one element in tailpipe emissions can’t be
"cleaned up" – carbon dioxide (CO2). This is the
principle greenhouse gas linked to climate change. Every gallon of
fuel that is burned produces about 20 pounds of CO2. The
bottom line: the more fuel you use, the more CO2 you
produce. And one of the best ways to cut fuel consumption is to
avoid idling. After all, it gets you nowhere.
How can only
one gallon of gasoline burned by a car or light truck produce 20 lbs
of carbon dioxide (CO2)?
Two factors contribute to the high output of carbon dioxide (CO2)
per gallon of fuel burned. First, fuel burns in the presence of
oxygen that it gets from air. Since air is only one-fifth oxygen,
large quantities of air are needed to burn gasoline. Second,
gasoline is rich in carbon, which is converted to CO2
when burned in the presence of oxygen. Because large quantities of
air are required to burn gasoline, large amounts of CO2
are produced. If you’re a typical motorist who drives 13 000 miles
each year, you’re emitting about four and a half tonnes of CO2
per year – that’s three times the weight of your car!
Is it important to idle my vehicle for a few minutes to warm up the
engine, especially in winter?
No. Although this is a common practice among motorists, it’s also
wasteful and damages the environment. Tests show that you need no
more than 30 seconds of idling to circulate the engine oil before
you can drive away on cold days. Anything more just wastes money and
produces needless greenhouse gas emissions. Remember, more than the
engine needs to be warmed – so do the tires, transmission, wheel
bearings and other moving parts. As well, the catalytic converter
doesn’t function at its peak until it reaches between 400°C and
800°C. The best way to warm the engine and all other components is
to drive your vehicle.
Is it more economical and fuel-efficient to leave my car running for a few
minutes than to constantly turn it off and on?
No. If you’re going to be stopped for more than 10 seconds (except
in traffic), you’ll save fuel and money by turning off the vehicle
and then restarting it when you’re ready to drive again. Every 30
minutes of idling costs you nearly one-tenth of a gallon in wasted
fuel – and more than three-tenths of a gallon if your vehicle has an
eight-cylinder engine. As well, restarting a car many times doesn’t
wear out the battery and starter motor too soon. And catalytic
converters stay warm for up to 25 minutes after you turn off the
engine, so frequent stops and starts don’t produce the large amount
of harmful emissions seen with cold starts. There’s no question
about it – idling gets you nowhere. Instead, it wastes fuel and
money and damages the environment.
Can idling damage my car’s engine?
You bet it can! Because the engine isn’t working at its peak
operating temperature when it’s idling, the fuel doesn’t undergo
complete combustion. This leaves fuel residues that can contaminate
engine oil and damage engine parts. For example, fuel residues tend
to deposit on spark plugs. As the amount of engine idling increases,
the plugs’ average temperature drops, and they get dirty more
quickly. This, in turn, can increase fuel consumption by four to
five percent. It’s a vicious circle of wasted fuel and needless
greenhouse gas emissions. Excessive idling can also let water
condense in the vehicle’s exhaust. This can lead to corrosion and
reduce the life of the exhaust system.
How much fuel
am I wasting, and how much CO2 do I produce by idling my
The cost of idling your vehicle for 10 minutes every morning can add
up. You use about 0.026 gallons of gasoline for every 10 minutes,
which costs us about 5 cents. This adds up to about 9.5 ounces of
Carbon Dioxide for those 10 minutes. It may not sound like much, but
it all adds up. Many people idle in the morning, at the ATM, at the
drive-through for lunch, then waiting to pick the kids up from
school. How long do you idle each day, each week, each year?
And remember, millions of motorists have fallen into the idling
What are the most common reasons for
Warming up a vehicle is the most common reason drivers give for
idling – in both winter and summer! We also idle a lot at
drive-through windows, when we are waiting on someone, and when we
wait at railway crossings, wait to park, run quick errands, stop to
talk to an acquaintance or friend, prepare to leave the house, wait
to get gas – even wait in line to get our car washed. All of these
situations waste energy and produce needless greenhouse gas
emissions – and they are all avoidable.
What is the
"profile" of the typical idler?
It’s safe to say that most motorists
do some amount of idling. However, Canadian 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
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:
- Minimize warm-up idling. This is especially important in
winter, because emissions can double in a cold engine. Drive away
after no more than 30 seconds of idling, assuming the vehicle’s
windows are clear.
- Use a block heater to warm the engine before you start it.
This reduces engine wear, improves fuel efficiency and reduces
emissions by up to 20 percent in cold conditions. Use an automatic
timer to turn on the block heater two hours before you plan to
start the vehicle.
- If you’re going to be stopped for more than 10 seconds, turn
off the engine. Never leave the vehicle running while you zip into
a corner store or fast-food restaurant – it’s hard on your
pocketbook, bad for the environment and an invitation to car
- Avoid using remote car starters. They encourage you to start
your car before you’re ready to drive it, which just means