photo: Shaun/iStock

Why Your Block Heater is Essential in Winter

By AMA Staff

A cord dangling from a vehicle’s hood is as common a sight in Alberta as Roughriders jerseys in Saskatchewan, or yoga mats in B.C. It’s basically our provincial shorthand, signaling to other drivers that the coldest winter temperatures won’t keep us down.

But have you ever wondered how that little cord (and the block heater it’s attached to) does such a big job? In this month’s Auto Expert, AMA’s Randy Loyk—a Manager in Automotive Services with four decades of industry experience—has the answers.

I know to plug in my car when it’s -15 C or colder. But what does that do?
The electrical cord connects to a heat coil in your engine block, heating up the antifreeze and preventing it from getting cold enough to affect your vehicle’s performance and components.

What type of negative effects are we talking about?
When your engine gets too cold, your vehicle’s motor oil thickens, which in turn increases the amount of work it takes to turn over the components in the engine. Essentially, it’s harder to start your car. But there’s another side-effect: When the oil gets too thick, it’s hard on your engine’s moving parts and poses a risk of either flooding or damaging the engine due to decreased oil flow.

Get to know your vehicle’s battery, and learn how CAA Battery Service can help you in winter—and throughout the year

What are the benefits to plugging in a block heater?
Quicker warm-up times will improve fuel efficiency, as the engine doesn’t need to work as hard. You’ll also see less wear on those internal engine components I mentioned, due to quicker lubrication. And if you’re one of those people who likes instant gratification—and really, who doesn’t?—it’s nice to know that when an engine’s coolant fluid has been warmed by a block heater, you can start drawing warm air into the vehicle’s cabin almost immediately.

Do I need to plug in my car overnight?
Although many Albertans keep their vehicles plugged in all the time during winter, it’s only really necessary for three to four hours prior to use. A block heater timer will do the trick and save you money on your power bill at the same time.

Do all vehicles have block heaters?
While most vehicles sold in Alberta come with block heaters, those that come from out-of-province often don’t (the same goes for many exotic cars). The tell-tale sign is the presence of a cord under the hood.

What are the types of block heaters?
A standard block heater warms the engine coolant, which warms the engine and motor oil. Then there’s a recirculating coolant heater, which circulates the coolant and warms it at the same time, ultimately warming the engine and motor oil. And with a lot of German cars, we see oil pan heaters, which are heating elements that are secured on the oil pan to heat up the engine oil.

Which block heater is best? And where can I get it installed?
Because every vehicle is different, talk to your mechanic. An Approved Auto Repair Service facility will be able to guide you in the right direction and ensure your car is ready for Alberta’s cold winters.