Will the Prius Prime use gas even if in EV mode?

There is a max speed for EV mode.
If temp is below 16°F and heater is used
If defroster is used.
Just to name a few

 

84MPH.

 

135 km/h (84 mph)

 

Turn on the eco gauge on the multifunction display. In the EV mode, the EV icon is green and when the ICE kicks in, it's grayed out; so, it's hard to miss the ICE running. It also displays the battery percentage.

 

P.S. You really can't completely avoid using any gas at all because..........if you do, the gas in the tank will go "stale" and gum up the works.
I think the Prime will automatically force you to use some gas every 6 months or so.

 

I generally take mine to the gas station once every 2-3 months, and put in 2-3 gallons each time.

 

I'm not sure why anyone keeps asserting this, in the face of so many Prime owners saying otherwise.

 

OK, so what really IS the truth ?
Is it another model that does that ?
Or does it just pop up a reminder warning that you need to use some gas ?

Or are you saying that it does NOTHING and will just let you keep the same gas in the tank until it is 5 years old without any warning ??

So straighten me out please.
I will try to remember the answer.

 

My understanding from multiple sources is that the Volt does/did so, but personally don’t know either way in the case of the Prius Prime. I have never kept enough gas in the tank to find out.

 

Perhaps the only difference then is just simply noticing when its running. It’s pretty quiet, usually. The hybrid-usage display helps with that.

 

From an older post from Lee Jay about the windshield defrost:
It pumps heat from the ICE coolant through the air conditioner evaporator coil with the AC running to dehumidify that air. That means the heat and the air conditioning are on at the same time.

It can't use the heat pump for the front defrost because it is using it for air conditioning, so it has to turn on the engine.

 

If all of your travels have been really EV mode only and you did not cause the engine to come on, then your Eco diary log would show the maximal mpg 999.9mpg for the last 30 days. Anything less than 999.9mpg, you used some gasoline for that day. This is also true for the ODO corresponding or even Trip Meter corresponding mpg on the dash. If the car was never driven on the engine using gas, it will show 999.9mpg. However, chances are that the car was driven some miles with the engine using gas prior to you purchasing the car, so the dash mpg indicator is most likely to be less than 999.9mpg.

Since you are in Canada, the unit is set different IIRC. I am not sure what 999.9mpg is in Canadian units. @Tideland Prius may able to help me here.

If indeed, you have had 999.9mpg for the last 30 days on the Eco Diary log, then your gas gauge is off. Maybe it was not full tank at the dealer?

 

Electric heating is effective most of the time for removal of condensation from the windshield. So, just using that option on the screen is a good first step. Most of the time here in Minnesota, that's all I need.

Pressing that dedicated "defrost" button will fire up the gas engine, since you are instructing the system to also dehumidify. The purpose of the heat-pump will then change to the role of A/C and warming will come from the heated coolant.

Think of the button as MAX defrost. It's there for your convenience, but often not necessary.