I know it can get very cold in Ottawa in the winter. Are automobile engine block heaters common/necessary? If I move a car from the US, would it need to be retrofitted?

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There is no perfectly correct answer to this question. Block heaters aren't uncommon in Ottawa, but lots of cars don't have them and get along okay.

The last new car manual I read recommended that if you have a block heater you should use it only if the temperature was going to be below -18C, suggesting that they are 100% certain that a properly working car will start at temperatures above that. According to this Ottawa averages less than 20 days per year where the low temperature reaches -20C or below, so following the recommendation would mean you won't get a lot of use out of the block heater. My experience is that if you use synthetic oil and don't try to get more than a few years out of your battery you'll have little to worry about above -30C with a modern car, and in Ottawa it is rarely that cold. On the other hand, if you do see a <-30C morning you may feel very smart for having bought the block heater.

I think you wouldn't regret buying the block heater (and if you move somewhere further north block heaters become standard equipment) but if you don't buy it you'll rarely have difficulty in Ottawa since it isn't that cold. You sort of need to decide for yourself whether you prefer to feel perfectly safe that your car will start under all conditions or would be happier not spending the money.

Do buy snow tires, though.

  • There is no perfectly correct answer to this question. Actually, this is exactly the information I was looking for. Thanks! Aug 22, 2017 at 16:19
  • I live in Saskatchewan, which is much colder, but I would have a block heater anywhere that temperatures get below -15 regularly. A car may start without one, but it will start more easily with one, and warm up more quickly. Also, contrary to the normal behaviour of many, it's best to only warm up your car for about 30-60 seconds, and then drive gently until the engine starts to warm up, to reduce unnecessary wear and fuel consumption. (I tend to keep the heater on a lower fan speed setting and ease it up as the temperature gauge goes up. This speeds up how fast the engine warms up.) Dec 26, 2017 at 14:31

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