Is 1 hour long enough for a block heater?
One thing that most can agree on is that the maximum amount of time you should leave the engine block heater plugged in for is four hours. Any more and you're just wasting electricity. You should also plan for plugging your vehicle in for at least two hours to ensure it will start. via
Should I unplug my diesel before starting?
Expert Reply: You'll want to unplug the block heater before you start the engine for a couple reasons. Mainly so that you don't accidentally drive off with it plugged in, but also so that the extension cord would possibly get wrapped up in moving parts or hot components. via
Do you need a block heater if you have remote start?
Although remote starters allow you to warm up your car without going outside, they're most useful when it isn't cold enough to warrant a block heater. However, it is still cold enough that jumping into an unheated car would be uncomfortable. via