2020 Prius Prime and Extreme Cold...

Here in Minnesota, we have been experiencing Winter warmer than usual. The outcome is just like what you have observed.

Lows have only been below -10°C (14°F) a few times so far. That means much of EV range has been shared with heat-pump operation. Resulting EV range has been around 35 km (21 miles) for my usual mix of driving. With mostly highway, I have seen it drop another 5 km (3 miles). None of that is a surprise. It's routine for me driving a PHEV since 2012.

When the warm weather returns, so does the EV range improvement. My results in Summer are very close to yours too. My longest EV range also ends up being 55 km (34 miles). Seeing even higher, like those who live much further south, is something I can only imagine.

As for calculating operation costs, I don't bother. My recharging at home is done off-peak (late night hours), to get a discount from my electricity provider. When taking trips to visit my sister-in-law's family in Wyoming, the consumption at 80 mph (129 km/h) is an indulgence I can afford... and MPG is still more efficient than everything else I encounter along the way. Those kids are growing up fast and there aren't really that many opportunities to visit.

 

"hydro", for anyone scratching their heads, is electricity.

 

Hi Darrell

Yes, on range alone your numbers are definitely in the ballpark for urban Wpg driving. I have met a few Prime owners in the city who also report roughly the same as well.

In the end, the "operating costs" depend on your daily commuting requirements and whatever else you add to the mix (like Indoor parking, grid-tied solar, etc).

Cheers

 

When I first got the Prime, it would estimate a 32.6 km range when starting, probably because of the heavy use of heating and defrost. But after a few weeks, despite not really using any less heating, it appears to have adjusted (and become better at predicting usage) and now indicates a higher value, usually in the 35-36 km range. Can't wait to see 55 km in summer!

 

Certainly our cold weather is no comparison to OP's location. It has been relatively mild winter. Unusually cold Nov was the coldest month so far. Our average Jan high is 20F (-6C), and average low is 2F(-16C). With those temperature, I use HV for heating and mix EV for driving after the engine has warmed up, and try using the HV intermittently to keep the coolant temperature high enough so the engine does not go through the warm-up cycle again.

I am currently seeing 48.2miles (77.6km) on my GOM (Guess-O-Meter) with a full charge.

 

Set your cabin temp as low as possible. Fan will still race like crazy, but it might help some.

I can't imagine that cold, btw. I start getting blisters on my finger tips and knuckles as soon as temps flirt with zero (C) here.

It's been unusually cold for us the last little while (around -6 to -8 today (C)), and snowing heavy. I'd guesstimate a foot right now, and no signs of slowing down.

Don't even think about venturing out right now. Saw a couple of RAV4 go by...

 

That's the opposite of what we suggest. For battery longevity, waiting as long as possible before beginning the charge is best. The added benefit of that is you get to take advantage of the warmth resulting from the act of charging. The warmer battery provides more EV opportunity, even in extreme cold.

 

While I agree with John on the benefits of timing the charging so that it completes just before you leave the next day, I have found the Prime to be less affected by the extreme cold temps when left plugged in than any EV I've owned before. For instance, delaying the charging event on the Model S was pretty much the best way to heat-up the battery pack. Later, this is something we also briefly did on the Ioniq.

In my case now, as long as both Primes remain plugged-in one can actually see and hear both cars doing their "thing" regularly. We can hear fans running (I assume battery heater cycle) and also see the 400-600 watts of power being pulled from the EVSE by each car. Of course, the colder it is, the more frequently these events happen.

On the coldest days, I also leave the car's block heater connected to a timed 110V outlet just in case the fossil engine ever needs to start during my commute (to minimize engine wear on cold start). Given my short commutes of just 12Kms, it rarely does start in part because I also wired a compact auxiliary cabin heater (~200W from Canadian Tire) to the block heater that will run whenever the block heater cord is plugged in. This way I have a much warmer cabin just before I drive off the next morning which is good for me and the battery pack.

This arrangement happens to have worked VERY well for me over the years with the added benefit of the newer block heater on the Primes drawing only half of the power of all other fossil vehicles I've owned previously. No joke. This means that even some public 110V block heater outlets, the plugs will not trip with the block heater and cabin heater both on. Truly a bonus for me in my parking ramp downtown.

I literally drive almost 100% EV all year round and in the coldest weeks of the year, my range rarely drops below 40kms. As an example, my 2018 has approximately 20K Kms and an average of 0.3 L/100km (or 12.1 KWh/100kms) on the odometer and just about all engine ON events happened on long trips totaling less than 1,000 Kms.

Cheers

 

Based on the power display in Hybrid Assistant, the seat heater uses an almost negligible amount of power even on high. It's maybe 100W, whereas the heat pump is 1-3KW. I don't have a steering wheel heater, but I assume it would also be low. So it makes sense to use that heat as much as possible to minimize the amount the cabin heater needs to run.

The battery is probably fine, but using the heater at that temperature will cause the engine to run. The colder it is and the more heat you need, the more the engine runs to maintain coolant temperature. It's not ideal for the battery to stay fully charged for a long time, but I think it's still important to keep plugging in so the battery heater can keep the battery warm. If the battery freezes, the rate at which it can be charged has to be severely limited to avoid damage. We can only assume the car will protect the battery as needed, but if the battery is above freezing the car probably works more efficiently. It would be interesting if you have an ODB dongle and Hybrid Assistant app to see what temperature the battery is.

 

I live in Minnesota and this is my 8th winter driving a plug-in Prius, what you describe as a problem isn't something I have encountered. The description gives an impression water was allowed pool. Spraying windshield-washer fluid (undiluted, of course) from time to time prevents freezing, since that pool will have some anti-freeze in it (which contributes to draining).

This video I just published (literally, my most recent commute) shows frequency of wiper use under very messy conditions...

 

Frozen wipers are normal occurrences in our region, but that usually happens when a car is parked and wipers down with freezing rain or snow melting after driving. We routinely lift-up the wipers when the car is parked in inclement weather in winter. Now, once the ice is cleaned and windshield defrost is operating, I have never had wiper getting stuck frozen while driving in the snow down to sub-zero F (-18C). At this temperature, windshield fluid often refreezes instantaneously even with a warm cabin and defroster on, so I try not to use the wiper fluid on those cold days.

 

On older Toyotas you could turn the wipers on and off very quickly, and it would park the wipers on the visible part of the glass. I haven't been successful getting the prime to do that, except once when it parked them slightly higher than normal.

 

Quick question: The washer fluid you got, is it still the same the dealer had supplied on delivery?

I'm asking this because my daughter reported a similar issue while returning home in the 2020 Prime. Next day, I then noticed the washer fluid was heavily diluted and definitely not performing like the usual Rain-X fluid I usually buy (rated for -40C). Since then, I emptied the reservoir and refilled with Rain-X. Last night over a similar trip back from Iles des Chenes, she noticed that neither the wipers froze nor there was any large amount of ice forming around the windshield.

Perhaps a higher rated fluid will also work for you?

 

Out here I get Toyota Washer Fluid, rated -40C IIRC. Not sure if it's that much better though. I've seen some fluid (might have been the Toyota fluid) freeze on the glass, just below 0C.

This was parked, just warming up, so no windchill factor.

 

Mine came with soapy water. I'd hope they give you something more useful in Canada.