3 Engine Cold Start Urban Legends

2019/12/03

Winter can be a stressful time for your car as the cold temperatures, snow, and ice strain your vehicle’s various systems. Over the years, a virtual cottage industry on winter maintenance and driving habits has sprung up across Canada, with friends and neighbours sharing tips in a bid to get through the chilly season as problem-free as possible.

Unfortunately, a fair amount of this shared wisdom—especially with regard to warming up a motor—isn’t entirely accurate. Let’s take a quick look at three engine cold start urban legends.

1- Your Car Needs to Warm Up

There’s a grain of truth to this belief, but only under one specific set of circumstances. If you own an older vehicle that has a carburetor, you do need to warm up the engine before heading out on the road to efficiently generate enough power.

For everyone else—keep in mind that the last carbureted vehicles disappeared back in the 1990s—there’s absolutely no need to wait for your car to be completely warmed up to drive. Today’s fuel-injected automobiles have a computer and sensors that adjust the amount of fuel used based on ambient and internal temperatures. This means your vehicle will run just fine when it’s dead cold out.

2- Cold Engines Use More Gas

Again, this is more or less true, in the sense that, on average, winter’s chill reduces a gas engine’s efficiency by about 12 percent. The thing is, letting your engine idle to warm it up before heading out on the road doesn’t help at all. Natural Resources Canada looked into the issue by testing three vehicles at minus 18 degrees Celsius. They discovered that the longer each vehicle idled, the more fuel was wasted during the drive immediately afterward.

In short, engines use more fuel in the wintertime, but “warming them up” doesn’t make a difference. In fact, it just makes things worse.

3- Block Heaters Weaken Your Engine

Engine block heaters can be a boon in regions where temperatures regularly hit minus 30 degrees Celsius. By keeping the engine oil and the block itself warm, these heaters help reduce friction and wear caused by cold starts, extend battery life, and reduce starter load.

You may have heard that once you start “plugging in” your vehicle, you have no choice but to keep doing so because the engine gets used to being warm and won’t start under any other conditions? There’s simply no science to back up this claim, so don’t be afraid to take advantage of a block heater when the weather turns ugly!

Check out all the seasonal maintenance services available at any of our 600 NAPA AUTOPRO shops for your car routine maintenance and repairs. For more information on cold engine starts, chat with an expert at your local NAPA AUTOPRO service centre.

By Benjamin Hunting

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