Engine Maintenance Mode

That’ll be interesting to hear!

I have rarely, but occasionally, seen the ICE kick in for no readily-apparent reason, given “the rules” I’m aware of for when it kicks in — over 84MPH, turn on the main windshield defroster, really-low temps (don’t remember the threshold number off the top of my head, etc.). Most cases, it’s been upon accelerating into a right turn onto the main highway to my place of work. Not clear why that would trigger it...

 

this will be interesting. i've read posts where people swear they reached over 2,000 miles

 

I’ve reached 250 miles so far and I turn the engine on every time I need to accelerate .

Once I’m up to speed, it’s EV until it’s gone.

But this method has gotten me to work and back and not left any charge in the battery. The gas gauge is still at the full mark.

 

That's only if your daily drive need is always within the EV range. Unfortunately, my PRIME's engine will come on every day.

 

I haven’t read all 785 pages of the manual yet, so you’ll have to help me with this one.

 

However, FWIW, much more common for it to *stay on* for no obvious reason, than to *turn on* for no obvious reason.

 

That’s wild! I’ve never seen that on my P.Prime...

I’ve never tried EV Auto mode (no interest in it). Is EV Auto mode “sticky,” so to speak? That is, unlike EV vs. HV, does it remember EV Auto after you power down and back up again?

I’d be surprised if so, but EV Auto is at least different from EV and HV in that it has its own dedicated button.

 

Not sure about all of that, I push the switch from EV to EV/HV and the gas engine kicks in as I’m needing power to climb the incline.

So I guess I have more reading to do, but I’m the interim, I’ll play the EV Auto role.

 

So, just to make sure there’s no confusion: there is no “EV/HV” mode. The EV/HV button toggles between EV and HV modes. There are three modes (in this particular sense of the term): EV (the default), HV, and EV Auto modes.

Since I don’t think I’ve ever tried EV Auto, I personally don’t know what happens when you are in EV Auto and then you hit the EV/HV button, other than that it presumably goes out of EV Auto mode.

 

Really? EV mode? We’re talking Prius Prime here, not PiP, right?

 

After getting in the prime this morning and looking at the buttons, I see what you are talking about now: EV Auto is the button next to the HV / EV button.

That’s what I have been cycling between .

193 mpg on the way home with 2% left hen I got into the garage.

 

Ah. I *think* that’s the way EV Auto is expected to work:

Again, as far as I can recall, I’ve never used EV Auto, but I gather it’s roughly comparable with the PiP’s barely-EV EV mode. Essentially, after warm-up, it’s totally EV-all-the-way! Well, as long as you don’t accelerate faster than a Yugo, drive faster than a bicycle, or that butterfly in Kansas doesn’t sneeze too suddenly! (OK, I’m exaggerating a little there...)

Personally, I think EV Auto would have been vastly more interesting if they’d defined it as something like “EV under 50MPH and HV above 50MPH.”

 

I started my trip to New Brunswick in EV Auto. 25 MPH for the first 3 miles, 50 for 5, 30 for 2, 40 for 2, 50 for 6, mix of 35 to 50 for 4. It was all EV, I switched to HV when I had 8 miles EV left so as to save some for the end of the leg. The car pretty much held those 8 miles while in HV.

From prior usage the car will stay in EV when in EV Auto unless you push it or you run out of EV distance.

 

Or, perhaps even better, define EV Auto as, “run the ICE when, and only when, it can operate at very close to its peak efficiency.” So, in short, fire up the engine if, in doing so, it would be operating at, say, 35% efficiency or higher (the ICE’s peak efficiency is ~41%); otherwise, shut it off completely and drive electrically-only.

 

I treat it similarly: if I hurt my EV distance by having to climb a hill or get into the freeway and up to speed, I swap to hv mode and “ride it out”, then swap back to EV Auto.

Very impressive car.