Heater in Extreme Cold

I've found in extreme cold turning ECO mode off really helps get heat quicker/hotter. We've had a rough cold snap here the last month also and It's been wicked!

 

"I have been selecting floor and defrost and that keeps it comfortable"

Somtimes using floor and defrost turns on your AC compressor at the same time. To heat up your car quicker use selection foor/front dash and make sure your outside fresh air is off. Also, make sure the auto temp. control button is off.

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I have a C4 and in the past couple of weeks it has been below -10°F on the 18 mile drive to work. The car warms up quickly and I did not notice any loss in cabin heating performance. I assume that all Prius C's have auto climate control so I don't understand the need to manually control the fan or temp settings. Perhaps the high altitude in Colorado makes a difference in heater performance (it's only 900 ft. elevation in Indiana).

 

Look into grill blocking.
http://www.cleanmpg.com/forums/showthread.php?t=17560

 

Block the grill so the engine can stay warmer, and inside the cabin, use the defrost button vs. the floor vent- for whatever reason, it warms up the cabin faster and more effectively. Also keep the fan speed in the low speed range for the first little while.. You might be tempted to go with a higher fan speed, but that just cools the engine down faster while it is trying to warm up. Use the temperature dial- I set it for 22C- don't crank it because the system actually adjusts how much engine coolant goes into the cabin heat loop based on this setting, and opening it all the way just slows down engine warm up and cabin warm up.. In addition to keeping the temperature setting at an appropriate level, I generally never go above 2-3 bars on the fan unless the windows are really fogged up and I need them cleared fast and I have no problems with heat up here in Canada where it's -20C in the mornings.. If you want to take the edge off the first couple of minutes before the engine has warmed up enough to start providing cabin heat, I'd suggest spending $20 at the auto parts store to buy one of those heated seat cushions that plug into the lighter socket.. They are amazingly effective..

 

Get a Prius engine block heater. Inexpensive and it works well to have a fairly warm engine coolant as you get in the car on these cold mornings.

 

I have done this a few mornings recently, and when the wind chill is -21F or worse in the morning, my Prius C II *does* warm up a LOT faster with ECO turned off. I just don't worry about MPG in the winter now, it sucks in the cold pretty much no matter what I do. I'd rather be warm faster & spend a few extra bucks than wait forever for the windscreen to be defrosted & my extremities to have feeling in them.