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Letting Your Car Engine Warm Up Is a Huge Waste of Time and Money

Quit idling and just let 'er rip

Quit idling and just let 'er rip

The practice of letting your car's engine "warm up" for a few minutes, allowing it to gracefully awaken from its arctic slumber, is deeply ingrained in the Tips That Help You Survive Winter everyone from Minnesota knows.

It makes sense, at least to people who know nothing about cars. It's like the mechanical equivalent to stretching before exercise. But studies done by both the United States and Canadian governments found cars don't benefit from idling at all.

See also: Minneapolis City Council Passes 'Idling' Ordinance

"Excessively long warm-ups cost you money, waste fuel, and generate unnecessary greenhouse gas emissions that contribute to climate change," write the authors of a study done by the Canadian government.

The authors of another study commissioned by the U.S. government explain:

"Major vehicle manufacturers and suppliers hold the view that idling modern engines is not only unnecessary but undesirable. Owner's manuals often advise against idling and encourage 'ecodriving' as a way to increase fuel economy and reduce emissions."

Cars nowadays no longer use carburetors -- which do need to warm up to work well -- to mix air and fuel. Instead they rely on computerized sensors and electronic fuel injection.

In fact, Minneapolis actually passed an ordinance back in 2008 that made it illegal to idle a vehicle for more than three minutes, punishable by a $200 fine.

Now we know that many people warm up vehicles not for the engine's sake, but so they don't have to experience the distinct displeasure of gripping an ice cold steering wheel, shivering while driving with hunched shoulders into work every morning.

We get that, and Minneapolis does too: If the temperature drops below zero the anti-idling ordinance does not apply.

Send news tips to Ben Johnson.