What Exactly does EV Auto Do?

i have no idea what you are talking about. why are you always so angry?

 

I believe those are the city numbers.
EV is more efficient, but the gap is likely lower at higher speeds. Then the energy in the battery is a more limited resource compared to what is in the gas tank. Better to use the gasoline on the highway, and passing, and save the limited battery charge at lower speeds where the most distance can be driven on it.

The default setting is EV mode. So people that just want to drive the car have to think about putting it in EV Auto.

 

Agreed about saving the EV charge, but EV Auto mode has nothing to do with this. You have to manually push the EV/HV switch to drive in hybrid mode.

Off the top of my head, electric motors are like 90% efficient vs. 40% for the ICE. Running in EV mode will always be more energy efficient than using the gasoline engine.

 

I've wondered at EV-auto also.
One possible answer (unverified) is that Prime uses the ICE when it can operate at some efficiency level or above -- E.g at least 40%.

So low power situations would be all battery and high power situations would be part battery and part ICE

I'm tempted to think that the three modes have these characteristics:
EV: ICE off
HV: Battery SOC kept within a narrow range of the SOC when HV mode enabled
EV-Auto: Battery used to keep ICE efficiency high

This is just a guess, and no Prime to play with yet

 

This is what the manual says about EV Auto:

When a sufficient amount of electricity for EV driving is remaining in the hybrid battery (traction battery) after charging*, the operation mode can be switched to EV auto mode.Switching to EV auto mode make powerful driving possible by using both the gasoline engine and electric motor in a driving condition that requires large driving force, such as when passing a vehicle on a highway or driving on a steep slope.

I've driven at highway speeds in EV Auto mode and never had the ICE come on.

 

PASS a car on the highway

I take that snippet you quoted to mean that the ICE will be invoked when the driver asks for more power than the battery alone can supply. I thought that happened anyway, when in EV mode.

 

What happens if you leave it in EV mode and the battery runs out? Does it switch automatically to HV mode?

 

Yes.

 

Could be that EV uses dual motors drive while EV auto does not. If this is the case then:
In EV mode max power is 68 kW (limited by battery / electronics), so passing on the highway could be somewhat slow.
In EV auto mode max EV power is 53 kW (MG2 rating), in very high power demand ICE is joining to a total of 98 kW, so passing on the highway is quicker.

 

My guess is that it is just the PiP's EV mode, but the larger battery and heat pump allow less use of the ICE.

 

the o/m makes no sense, there has to be more to it.

hasn't anybody tried it yet?

 

It surely in contradiction to what marketing people were telling all the reviewers that in EV auto the car automatically chooses the most efficient power source to handle demand...

 

OK.....so you start out in the default EV mode. What happens when the HV battery finally gets depleted ?
If that requires the driver to move a switch or knob to "activate" the ICE.....than that's stupid engineering.
And if you do NOT have to switch anything in EV mode for the ICE to come on when needed.......that sounds a LOT like automatic to me.

 

When the battery SOC reaches a level set by Toyota the car switches into HV mode. I don't know the exact trigger point but it is probably in the neighborhood of 0.5 kWh above the buffer if the regular Prius is something to go by.

 

There is a difference between needed because of low SOC (all EV miles depleted) = automatic switch to HV mode, and needed because of temporary high power demand (EV miles exist) = ICE coming automatically in EV auto.
Bear in mind that when EV miles depleted completely the car switches to HV mode and stays there, while ICE firing in EV auto there is no switchover, the car stays in EV auto mode (EV auto indicator - on) while the ICE is on and the car will resume EV driving once the ICE is not needed any more.

 

that's how ev mode is as well. the car stays in ev mode, and fires the ice as needed.

 

With the PiP - yes. With the Prime usually in all practical situations - no (except for some extreme conditions which are mainly to protect the system).

 

are you saying that if the prime fires the ice in ev mode, the car will then change to hv mode and the ice will be used after that?