Mine liked it when it got down to -30 here(MT) in December. Didn't like having to open and close hood to plug and unplug.I like the engine heater, is it needed? Probably not except in rare cases.
But it’s just easier on the vehicle, warms up quickly to defrost (MT), warms the oil about 10 degrees above ambient temperature and keeps the under hood temp a little warmer which the battery likes. No downside except a few cents for electricity as it’s on a timer.
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