Hey there, I posted a thread over in the general section about my trip from Alaska to Tennessee but I'm also looking for some more specific advice to this model of prius and it's handling in severely cold weather. I'll be on the Alcan hwy for about 4-5 days, and I'll be driving through temperatures of -10 or -20 and I'm curious if I should have an issue parking the car and leaving it off for a few hours while I sleep. I'm still wondering if I should invest in an engine block heater. I just really really don't want to wake up to a car that won't start in the middle of nowhere! I'm also considering leaving the car running with the heat on while I nap, since the gas engine only kicks on seldomly to recharge the hybrid battery so it should use minimal gas during this. Any suggestions would be greatly appreciated! Thanks guys!
The car uses a decent amount of gas when sitting with heat on because the engine runs out of heat much quicker than the battery loses charge. Not as much as a regular car, but probably more than you're thinking. There shouldn't be a problem turning it off, the Prius' "starter" is much more powerful than a conventional car's. Either way should work fine.
A block heater can be useful to improve gas mileage. You can leave your Prius running to keep the cabin warm if you plan on sleeping in your Prius. Other than that, you seem to be over thinking it, the Prius will be fine. (The new 2016 Prius Two Eco has a Li-on battery that warns against being under -20F, but the NiMH battery chemistry of your Prius is fine below -70F)
Prius engine has “starter motor” that has more torque that can ever be needed to start the engine. Friend told me that his started with just normal sound at almost -40c/-40F (without block heater). -50c/-58F might take couple of tries but HV-battery has enough charge for 100s of tries. So basically your cold start temperature is limited by your coolant and oil. Here is Russian cold start video at -50c/-58F (without block heater). Запуск двигателя Toyota Prius -50 по цельсию. - YouTube Block heater will reduce fuel consumption and wear. Interior heater will reduce fuel consumption even more as it will limit the needed idle time.
A block heater's a good idea, as long as there's access to plug it in. The part's somewhere between $60~80, installed shouldn't be more than $250. Me, I'd get it installed. FYI, we use one, year 'round. Two hours is a good amount of plug in time.
... and by the 12V battery's ability to boot up the computers and brake accumulator. While these add up to much less stress than the starter motor of a conventional car, a number of Prius owners still have run into problems with aging or seriously weak 12V battery problems in cold weather.
I'd make sure the 12V battery is in good condition. As long as the 12V can boot up the electronics, your car's good to go. If you have a place to plug in the EBH, I would install one. (AK doesn't require one?) The Gen 2 has a thermos heater that keeps the coolant warm. If you let the car run while you sleep, the engine will probably be running continuously to provide heat (your thoughts on coming on just to recharge the battery only applies during the summer or warmer temps when you don't require the heater) so you have to be careful of carbon monoxide build up. While it's not the same generation, I've had no issues starting up my 3rd Gen after a 2 week cold soak in -20°C temps. It was plugged in but I don't know what the power-on/off cycle was on that power outlet (it's not continuous power).
1. Since you are from AK, presumably your car has been exposed to temperatures that cold all winter? If you haven't had trouble with the car starting in the morning, why would it have trouble during your trip? 2. There is no problem leaving the car READY while you sleep so that the heater will work, just make sure you have adequate gasoline in the fuel tank and that your engine exhaust system does not have any damage to it. 3. The engine may turn on pretty regularly to keep the cabin temperature at a reasonable level given ambient temp of -20 degrees F, but I guess you'll find out when you try it. 4. As previously suggested, make sure your 12V battery is in top shape before you start your trip. That would be good advice regardless of the ambient temps to be experienced during the trip.
The Prius seems to deal with extreme cold much better than non-hybrids. While regular cars slow-crank and complain, the Pri hardly seems to notice (it's great having a 220V AC motor to turn the engine over). Snow performance depends a lot on tires, but I find it to do very nicely. I thought it was okay on the original Goodyears but very confidence inspiring on the Hankook H727s. Continental TrueContact is supposed to do even better. If you have an AC plug available where you park (the block heater would require this, correct?), you could run a cord inside for a small space heater, etc? You could carry a jump-box with you as an added precaution, in case the 12v gets too low. As mentioned, it doesn't take much current to boot up a Prius.
