Why in EV mode the gas engine turns on ?

There could be many good reasons. First of all, on a regular Prius isn't the engine always supposed to fire up a few seconds after you start the car? Did you have the heater turned on? It only works from engine heat, and the car is smart enough to start the engine when you call for heat. If you accelerated a bit too hard, that would easily do it. Did you drive more than about a km or so? That's all you can expect on EV unless you have a Plug-In model.

 

who did you see? i have never gotten more than a mile on flat ground at 10mph with a fully warmed engine. i think your expectations are unrealistic.
the car isn't really designed to be driven in ev, it's more gimmick than useful

 

I've never got more than a 100 feet or so, and I get a message, usually that speed was too high (only 15~20 kms/hr IIRC).

EV mode on a regular 3rd gen Prius is pretty much a novelty item. If the car is warmed up it can be useful, purely to move a car a few feet in the driveway for example, but that's about it.

It'll NEVER work for me, if the engine's cold.

 

Hey, I can go 40 miles on EV. Whoops... this is not a PRIME thread.

 

If you want to go farther without ICE but warmed up engine, you better to leave it in normal mode and drive the way not to start the ICE.
EV mode is to get the car away for a few meters without starting the engine.

 

It has to be possible. I mean last week someone told me on here that I need to reconditioned my HV bat because I couldn't make an entire mile on EV alone after I posted that my last mile stretch was limited to 25 mph so I had to P&G every 1/3 mile thus SOC would be right above 40% when I reach my parking space.

We want names, year model and make, and are these people on the internet or in real life?

 

have you considered a prolong battery rejuvenator? how many miles on her?

 

For isolated, short distances, it is possible to get a mile or slightly more on EV mode in a Gen 3, but the system will start the gas engine to recharge the battery and your overall mileage will suffer. It takes great patience and an egg on the accelerator to make it happen. I have reached 44 mph before the ICE started.

To the OP, you are better off accelerating to your desired speed, then relaxing your foot on the accelerator to get the ICE to shut off. In this manner, since you have more speed, especially with regen that occurs, it’s possible to get 2 or even 3 miles with no ICE. But, as was mentioned before, unless you have the Gen 1 plug in, there was no advertised “electric only” range. The battery is designed to be a helper, not the main source of propulsion power.

 

The Prius software moves in mysterious ways.
The Prius is also designed to create cleaner emissions, which require a warmed up engine. This will sometimes override any desires to be in EV mode.

When I owned my Prius I just didn't worry about it. It's not a full EV vehicle, so I trusted that HSD knew what it was doing.

I rarely used EV mode. I called it the "show off" the Prius mode. That is when I had new riders with me, that wanted to experience the Prius in EV mode, I'd press the button at low speeds and hope it would go into EV mode long enough for them to be amazed at how quiet the vehicle was, and what great gas mileage it was getting.

Or occasionally I'd press it when cruising a crowded parking lot looking for a parking space.

But I found really no other reasons to use it.
Once I was comfortable and familiar with the vehicle, I found I could usually coax or create EV mode just through how I was driving at the moment. In fact, it seemed to me I'd have better luck entering EV mode, just by modulating my speed, torque and demand, than I would when I pressed the EV mode button....which usually just resulted in the Prius telling me it didn't want to go into EV mode.

My expectations never were that I had bought an Electric Vehicle, and with a standard Gen 3 Prius any distance or miles in EV were just part of the whole Prius driving experience which is usually a blending of ICE and electric motor.

 

actually, for short distances, 23mpg is normal

 

We have times with a lot of short trips, when the mpg is horrible, but then (and this is a regular Prius) I think: yeah but it's been about 6 weeks since I last filled up, and that was just below 1/2 tank. It balances out.