From the Prime owners manual pg. 87; bold underlining is mine): ■Gasoline engine operation in EV/EV auto mode Even if there is a sufficient amount of electricity remaining in the hybrid battery (traction battery) and EV driving range (→P. 199, 215, 222, 239) is being displayed on the multi-information display etc., EV driving (driving using only the electric motor) may be canceled and both gasoline engine and electric motor are used depending on the situation (EV driving will be returned to automatically after EV driving becomes possible again). EV driving may be canceled automatically in the following circumstances: ●When vehicle speed is more than approximately 84 mph (135 km/h). ●When power is needed temporarily, for example when the accelerator pedal is depressed firmly or when accelerating suddenly.* ●When the temperature of the hybrid system is high. The vehicle has been left in the sun, driven on a hill, driven at high speeds, etc. ●When the temperature of the hybrid system is low. ●When the heater is switched on when the outside temperature is below about 14°F (-10°C). ●When the windshield defogger switch is pressed. (→P. 491, 501) ●When the system determines that the gasoline engine needs to be started. The gasoline engine may also operate in circumstances other than those listed above, depending on conditions. *: When traveling in the EV auto mode only ■Conditions in which the gasoline engine may not stop The gasoline engine starts and stops automatically. However, it may not stop automatically in the following conditions*: ●During gasoline engine warm-up ●During hybrid battery (traction battery) charging ●When the temperature of the hybrid battery (traction battery) is high or low ●When the windshield defogger switch is pressed. (→P. 491, 501) *: Depending on the circumstances, the gasoline engine may also not stop automatically in situations other than those above. http://www.toyota.com/t3Portal/document/om-s/OM47A88U/pdf/OM47A88U.pdf
It seems to have the same parameters as my Energi and if so you can expect winter/cool weather threads about defrosting=ICE activation. Looks like the heatpump is good down to 14f. That's crazy cold to me but to others a nice winter day.
that will be the difference maker over the competition. 14 degrees probably covers 80% of the market. even around here, it doesn't go below that very often.
It does say in the bold statement, when traveling in EV Auto mode only, not EV mode. So yes it will act like the PiP. I was reading about the Charge mode. It seems the best place to use that would be on the highway. Unsupervised!
It seems like some of the reporters were in EV auto mode then when they said the engine came on when they accelerated hard.
When going over 84mph, and when calling for heat below the heat pump's minimum is expected, but I think many will get caught off guard by the hybrid system being too hot or cold, or when defogging. You've been retired too long and lazing about in the bed all morning. It will get down to single digits and zero F for my morning commute. Which means it will be below 10 in Philly.
As my friend often says, the reason I get poor mileage in winter is because I have to run the furnace (the engine). And yes, 14F is a "nice warm winter day". Not here yet, but soon.
Agree, and the battery heater function will help too. Interesting: For Alaska and Canada there is also a "battery heater control" said to insulate the battery when the car is not used during 31 days of very cold weather, after 3 days of battery heater operating. Battery charging cable should be left connected obviously. For the hot areas: there is a new "battery cooling" option you can choose in which if you start charging when the battery is very hot, this function will automatically use the air conditioner to cool the battery while charging, it will be used for 30 minutes max. Charging time will be longer in this case. Details in the manual.
Ran it on a 90 mile trip this weekend. It was about 15 degrees. it did start out in EV mode and ran just fine, but the fan speed only got up to the 3rd bar, and it was warming up really slooow.. I put it into HV mode and the Prime warmed up pretty fast. So yeah, i think the heat pumps limits are really close to 15-20 degrees and that is why Toyota has the ICE starting up at 14-15 degrees.
