While driving today I noticed that on the energy monitor screen it showed the engine being used even though it says I still have 18 miles left on the battery. Any idea why that is happening? I tried switching into different driving modes but no change. I’ve only had the car a couple weeks and still trying to figure everything out. Thanks for any help.
There are several reasons for the engine to run and unfortunately, the manual doesn't list all possibilities Requested more power than the battery can provide due to cold/low temperatures Requested more heat than the PTC heater can provide Drove down a long hill (doesn't have to be steep) with regen Shifted to B on a steep down hill Selected HV (hybrid) mode I'm sure there are others but these are what I can think of off the top of my head. The 2020+ Prime seems to kick the engine on a bit more often than 2017-2019 versions. I think it's to preserve the battery life as Toyota extended the warranty to 10 years/150,000 miles for all States (and Canada too).
This is not the right time of year to figure out how the prime works. It will work much differently as spring rolls around into summer. This time of year the engine turns on when the computers detect a component is below the threshold temperature. If the car sits overnight during the winter, even while it being charged, the traction pack temperatures get pretty low and EV performance and range are adversely effected. One of the main features of the DrPrius app is the traction pack battery temperature. You'll see that when traction pack temps are between 80 - 90 degrees F most drivers will experience the Pimes best performance. When temps start falling and traction pack temps are in the 50s F most drivers will notice both decreasing performance and EV mile range. At 37 F (and below) ambient (outside) temps, the temperature gauge on the dash will blink for a few seconds, when you first turn on the Prime.
EV driving may be canceled automatically in the following circumstances: When vehicle speed is more than approximately 135 km/h (84 mph). When power is needed temporarily, for example when the accelerator pedal is depressed firmly or when accelerating suddenly. (EV auto mode only) 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 −10 ℃ (14 ℉). When the windshield defogger switch is pressed. When the system determines that the gasoline engine needs to be started. HINT: The gasoline engine may also operate in circumstances other than those listed above, depending on conditions.
