Drive Modes

Basic rule: slower speeds/short drives=EV, fast speeds/long drives=hybrid. There will be exceptions.

CHG mode will use the gas engine to charge the battery.

 

I will definitely use it on a long trip !
I don't know if it's true,but charge mode apparently is capable of charging the battery up to 80% in just about an half hour while getting not too bad fuel economy while doing it ! (maybe 42-44 mpg ?)
So why not have slightly worse fuel economy for about an half hour but afterwards enjoying emissions free driving in town ?
Somebody here tried it out for thirteen minutes and was averaging astonishing 48 mpg !
I think it's great Toyota thought of it !
You can use it but you don't have to,so the choice is yours !

 

There's already extensive discussion on this.

My opinion, not owning one yet, but having used it on two test drives:

I'll use it on long trips where I know I won't have the ability to charge at the stops and where I know I'll be doing short trips at those stops. This will save warmup cycles because I won't have to start the engine to make those short trips.

I'll use it before big high-mountain climbs to assure I'll have plenty of electric power all the way up the hill.

 

Hmm, if it's anything like the Chevy Volt's various modes, I can try to chime in. Feel free to correct me if I'm wrong.

EV mode is strict EV driving so long as the battery has a charge. Then when it runs out, it'll switch to hybrid mode, aka a regular Prius.

EV auto mode sounds like the Prius will use whichever power it determines is most efficient for what you're doing at the time. So on the freeway I'd imagine it'll run in hybrid mode, then when you jump off and do city driving, or get stuck in bumper to bumper traffic, it'll switch to EV mode.

CHG mode, if it's anything like the Volt's "mountain" mode, will force the gas engine to run to recharge the battery up to a certain amount, say 25-40% of the charge.

For the Volt, this gives the electric motor a buffer so that it can run with the gas engine to help you go up steep mountain passes at higher speeds, like say 75 mph. The gas engine, at least in the 2011-15 Volts, isn't powerful enough to go up steep inclines on its own, and if there's no battery charge, it'll give you a "reduced propulsion" message, and run slower until the gas engine has been given a few minutes to run to charge up the battery.

Note that in the Volt, by design you can never fully charge up the battery on gas alone. GM's engineers made it so you have to plug it in to get a full battery.

I'm guessing the Prime will also behave in a similar way, in that the gas engine will never fully charge the battery on its own. Partly because burning gas is the least efficient way to gain back electric miles, but also because that would defeat the purpose of plugging it in in the first place.

 

It will charge the battery up to 80 % !

 

Once the battery is close to depleted, it may start the ICE at high throttle positions.

80% max on Prime.

We think, but aren't sure, that a long decent will do it as well.

 

Ev Auto is about efficiency, not power output.

Most people are reporting that, in practice, it's mostly Ev.

 

Okay, that's not what the engineer said.

Regardless, it will do that at the end of charge anyway (I personally experienced it starting the ICE in Ev mode when I floored the throttle) and that's because that's when the battery no longer has the capability to run the motors in dual-motor mode at full power.

 

How does passing power compare to the liftback ?
Is it slightly worse due to the extra weight or is it hopefully even better ?

 

I personally couldn't tell the difference, but I didn't drive them on the same day. Months apart, in fact.

 

EV auto is how the PiP and Energi's work in EV mode. Many people didn't like this; they wanted pure EV operation while in EV mode.

With dual motor operation the Prime has more power available than the PiP did in EV mode, so pure EV became possible for it. The EV auto is there for when a trip in beyond EV range, and the driver doesn't want to manually determine when to use EV or hybrid mode.

 

As I said above, I got the engine to start while in Ev mode (not Ev auto) at a high throttle setting and a low state of charge.

 

He was averaging 48 mpg for the whole trip while in HV mode (i.e. deducting the two EV sessions), not only for the period of using charge mode.
We still lack info regarding performance and efficiency of this new mode.

 

We had one prospective buyer who had no place to plug it in. HE could use "CHG" mode to charge it up so he could then sneak around in EV mode.