Prime may start ICE in EV mode if Windshield Defogger switched on

anybody read the climate control section for a clue yet?

 

Agree. Unlike the PiP the Prime has a heat pump and heating will start if called for by temp set in this mode. Defrosting will be more effective with heated incoming air.
Only in very sever fog/mist on the windshield the defogger will be required.

 

Defrost mode is needed when there is fog on the inside of the window. When it's on the outside, just heat on the window will do the job.

 

If the car has time to pre-heat while on charge, 10 minutes of heat with fresh air should do both quite effectively when no one is in the car.

 

With the hybrids, the A/C liht one means the climate control will make use of the compressor as it sees fit. With heat coming from the ICE, this isn't an issue.

The Prime uses the heat pump in EV mode for heat, which leaves it without a way to dehumidify. So it could switch the HP to dehumidify, and then use waste heat from the ICE if needed.

And this is all just the long way of saying your experience Toyota hybrids climate control doesn't apply to their heat pump equipped PHEV.

The solution is easy. Don't heat the cabin.

The front defogger likely defaults to dehumidifying when turned on though. So even if the issue is outside frost, the ICE might turn on in the Prime.

Cabin preconditioning will help with inside fog, if the fogging is an issue at the start of the trip. In my experience, interior fogging is more of an issue while it is raining out. This means the fogging can happen at anytime during a trip.

 

If it is outside why use the defogger? With the prime, you will have other means of heating the windshield without starting the ICE, foot/defrost mode.

 

My Energi will display a notice that the ICE will engage when the Defrost button is pressed but...... it doesn't necessarily come on since it's based on the set temp. Ford also utilizes a MAX Defrost button that automatically activates the ICE.

Pre-conditioning in the garage and cracking a window BEFORE or at the very first signs of fogging helps too and with three people in the car here in cool, humid south Texas winters I can drive about 5 miles before needing defogging.

 

I was replying to the use of the defogger to remove or loosen frost and ice.
What offer means of heating the windshield beyond the climate control are there?

 

hair dryer?

 

I think that's meant as, aiming output at the defrost vents instead of using defrost mode?

In any case, this is a good use case for an electric heated windshield, which plenty of other manufacturers have...

 

i also was hoping for the electric windshield, but hopefully the heat pump solves most of the problems.

 

Any recommendation for a sarcasm smile?

 

I'm not a Prime owner, but I did test drive one twice.

First, at low power levels, it's not all that easy to even detect when the engine starts and stops. It's that quiet. At high power/RPM, it's easily audible.

I found the transition between Ev only driving and engine-assisted driving to be entirely seamless. The throttle response is the same and there's no detectable jerk or glitch when the engine starts and stops, even at high power levels.

In other words, it drives like an Ev whether the engine is running or not.