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A Few Extra EV- ELR Miles with Coolant Control

I know winter is about gone but here’s a tip I found on how to get a few extra EV miles from your ELR on cold days.

If you’re not plugged in to per-condition your ELR or Volt - rather than have your batteries provide the 5kw of current necessary to heat the cold; cabin / battery coolant for your trip, you can save some battery miles by pulling the hood latch which causes the range extender engine to fire up at "Idle" which quickly heats the cabin & battery coolant to 170-195 degrees. (Considerably higher that the heater circuit) This really heats the cabin are much faster than the heater circuit because of its higher temperature.

This also serves the purpose of a good warm-up for your engine so it’s not performing any real work on frigid days when it’s required to run. I usually pop the hood about 5 minutes before I leave then just re-lock it as I get in the car.

If the hood method is a pain for you – I recommend you just select the “Hold” mode as you start out of your driveway which will start the engine and pretty much provide the same results except at a higher rpm. I like the hood release method since it keeps the engine at idle. Either method barely sips fuel and it only takes a few minutes.

When using either method - be sure to select “Coolant Temperature” display on the panel so you can monitor the temperature, when I’m using the hold mode, I usually shut the engine down once it gets to “thermostat open” temperature, around 190 degrees.

Also keep in mind if the temperature is below freezing, the ELR’s processor will automatically start the engine to heat the coolant to 145 degrees then shut down and re-start when it cools back down to 122 degrees. It will continue to do this as long as the temperature is below 32 degrees. This relieves the burden of the excessive current needed to heat the cabin and batteries and also provides a more comfortable cabin temperature.

Another tip is; you can monitor your cabin / battery coolant temperature even with the “engine off “ any time by displaying the coolant temperature on the display. The element heater not only heats your cabin and battery, it also bleeds a small portion of coolant through the engine, so when you per-condition, you are also heating the engine as well, which is a good feature. You can monitor the coolant temperature rising when you precondition or use heat while under way.


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