Unnecessary internal combustion idling

I've been mostly content with my Prius Plug-in for nearly a year now. But, as a driver very consciously aware of what my car is doing, I have many complaints concerning the internal combustion engine igniting when not needed, or remaining on for far too long. I do my best to work around them, but I feel the need to enumerate my complaints and vent about them. Note I live in southern California where cold weather is extremely rare, and I consciously don't use the heater or AC.

1. ICE ignites when braking downhill on a full charge. I've heard users say this is necessary because if the battery is full, regenerative braking will overcharge the battery. Really? Why? What does a pure EV do in this case when it has no ICE backup? Why not just use the brakes? Or convert the excess charge energy to useful heat in cold weather, or just vent it when it's not cold?
2. ICE ignites if I step on the accelerator ever so slightly too hard. I understand that Toyota claims it needs to use ICE to deliver the extra power to the wheels asked for by the driver, but, sorry, I just don't believe that. The engine usually simply idles and does not power the wheels at all when this happens, meanwhile the wheels are still running on 100% EV power. I know this because I've become in tune to exactly when the ICE powers the wheels and when it's not. The easiest sign of ICE actually powering wheels is when the accelerator begins to vibrate and I hear the ICE rev up. The second sign is by watching the MPG meter. If you're cruising at something like 50 MPH, and the ICE is idling, you'll see it getting about 80-90 MPG. When it actually supplies useful power, it suddenly drops down to 50 or below.
3. ICE ignites if the car moves faster than 65 MPH. This seems totally arbitrary to me. For example, it does not matter if you're accelerating steep downhill in neutral, or on a level highway just very slowly accelerating past 65. You can watch the power meter the whole time, and even if it doesn't get anywhere near the (power) section to the far right, the ICE still ignites as soon as you hit 66. In those situations, why does it even think it needs any extra power? And to top it all off, all it really does is idle for at least a minute anyway.
4. It would be forgivable if when any of the above things occurred, the ICE runs only momentarily, but here's the kicker: If you immediately let go of the accelerator, decelerate to below 65 MPH, or even come to a full stop at a red light, the ICE still continues to run for at least a minute or two. Worse still, it idles for about a minute regardless of speed or power, then suddenly decides that it should power the wheels for a few seconds even if no variables have changed, and it does this for about 30 seconds more before finally deciding to suddenly pop back into pure EV mode. How you work around all of this? Stop at a red light, shut off the car, and restart it. As it powers on, it stays in EV mode, proving to you that it never needed to be sitting there idling in the first place.

 

Retired4999, I did actually read the manual, so I'm aware of all these factors, but I do not think any of them apply to the conditions I listed. I don't have any trouble with the ICE igniting randomly. I know exactly what I did that caused it to ignite, but I feel that in each of those situations, it either should not ignite at all, or at least should not continue to run idling for 1-2 minutes at a stop light.

 

Thanks for the recommendation. I've been considering picking one of those up for a while actually. I'll have a look at some of the data after trying it and post here again

 

That's the other thing that's even more frustrating to me. Maybe my car doesn't know whether or not I'm about to slam on the accelerator again any time soon, but I do, and I'm the driver. I really wish that I could force the vehicle back into EV mode again with a simple button. In that case, I could forgive the car for being dumb if it had a mechanism to allow the driver to control it.

I'll check out the ODB devices.

 

Also, here's another case in point. Just now, I went out on my lunch break to run an errand. I had a relatively short drive back to the office (about 5 miles), and I still had some battery juice left. I ran on EV for a while until I hit the 2 mile stretch of freeway, at which point, I deliberately switched to hybrid mode to conserve battery and let the ICE do the heavy lifting. But rather than the ICE doing any useful work on the freeway, it simply idled the whole stretch while my battery continued to drain due to the higher speed driving. When I exited the freeway, I switched back to EV mode, but the ICE kept idling even as I stopped at the light at the bottom of the off ramp. As I accelerated when the light turned green, the ICE kicked into drive mode as I heard it rev up, despite me deliberately selecting EV. It did this for approximately 1 more mile before it finally suddenly quit and dropped back into EV. Consequently, I had a mile of battery power remaining when I arrived at the charging station that should have been used on the road rather than the gasoline I actually have to pay for.

So, it's almost like the car does everything you tell it to do, but it does it approximately a mile too late.

 

I don't doubt that at all. But, since I myself am a software engineer, I find this frustrating. If only I could hack into the code. Also, Entune is complete garbage, but that's for another thread entirely.

 

Funny thing about that, though. Sometimes, like when going uphill, or when the charge has depleted down to where only HV is available, the ICE seems to only run as long as it's needed, then immediately shut down. If you start going uphill in EV mode, and you go into the power bar section, the ICE usually kicks in and immediately revs up powering the wheels. As soon as you reach the top of the hill, and you reduce power, the ICE immediately shuts off. Similarly, if you only have HV available, and you're in stop and go traffic, ICE kicks in as soon as the bar goes past halfway, then usually shuts down within a few seconds after reducing power.