Canadian idle: Should you warm up your car before driving it?

Warm-up debate gets pretty heated, but it's based on old facts

Should you warm up your car before driving it? It’s one of the more heated winter-driving debate topics, but experts say it’s a throwback to the days of carburetors. If you’re an old-school idler, here’s why you might want to rethink your position:

It’s unnecessary: Modern fuel injection, which eliminated carburetors and chokes, is much more efficient. With newer cars, the only reason to let the car idle is to get the oil circulating, but after 30 seconds that’s taken care of. Idle any longer than that, and you’re just wasting fuel and adding to greenhouse gases.

It’s inefficient: According to the Hinkle Charitable Foundation’s Anti-Idling Primer, idling forces an engine “to operate in a very inefficient and gasoline-rich mode that, over time, can degrade the engine’s performance and reduce mileage.”

It’s dangerous: Regardless of how long you warm your car up beforehand, always  remember this: Never warm up a vehicle in an enclosed area. Carbon monoxide is an invisible, odourless gas that builds up and can kill humans and animals quickly and silently, CAA notes in its winter driving guide. Similarly, always make sure your exhaust pipe is clear of snow. A blocked pipe can force carbon monoxide back into your vehicle.

Bottom line: Vehicles do not need to sit and warm up before being driven. This is especially true if you are using synthetic oils. These oils do not thicken up in cold temperatures like conventional oil and as such, they flow better in colder temperatures. Even on the coldest days, you need not idle any longer than 30 seconds before driving away, although if your main goal is getting into a toasty warm car with a fully defrosted windshield, 30 seconds isn’t going to cut it.