What temperature does the ICE "like" when it is first started?

john 1701 has many posts on this. i don't have a scan gauge, but mine warms up for 3-4 min./miles. interestingly, my wifes hycam will sometimes shut down after 30-60 seconds.

 

As covered in the FAQ, the way to deal with your particular issue is to simply shift into neutral while you go downhill and switch back to drive at the bottom.

 

In Eco Mode, the ICE will run until it reaches 130F. Not sure about Normal Mode since I never use it, but I've seen it posted around here somewhere.. I want to say 145-150F.. but not positive. Once its warmed up, there's a different temperature threshold before the ICE restarts, from what I recall.

 

I do not know if this was discussed in the FAQ, but the one thing to watch out for when switching to neutral when going downhill is to not get above about 47 mph. When you switch to neutral with the ICE off it will remain off. If you get above 47 mph you can overspeed MG1 and the ICE cannot come on to prevent the overspeed.

 

When I first got my PiP, I didn't have a plug in the garage and drove it like a regular Prius. I noticed the warm ups were very quick. It appears if the PiP has extra charge, ICE runs longer to do the plugin specific thing?

 

Good point. The threshold is not to exceed 62 mph. PiP will automatically start the ICE if it exceeds 62 mph. In neutral, it will not and would overspeed the MG1.

 

Thats been my observation as well.

In the mornings, if my ICE started from excess regen, it would run for quite a while (until it reaches 130F). But I never really feel the ICE kick in to assist before it shuts off. Going home, when I run out of juice and the ICE starts up, I'm climbing a hill. I always notice the ICE runs for a bit (maybe a minute or so) before the ICE will kick in to assist. In fact, on Friday, I think the battery ran down to 18.8% before the ICE kicked in.

To put it in perspective of miles, in the morning with a full battery, I'll drive for about 3-4 mciles (and that includes a few minutes driving in and out of the school parking lot when I drop off my kid) before the ICE shuts off. Coming home, with a depleted battery, I'll drive for maybe 1-2 miles before I feel the ICE kick in. I have to go through my logs to see what the temp is before the ICE kicks in on my way home, but I'm sure its not to 130F. Like you said, its probably because I completely ran out of charge so the ICE has no choice to but assist, even if its not fully warmed up.

 

Sounds kind of scary that to save a tiny bit of gasoline that one would risk damaging the PSD by inadvertently letting the speed get too fast. And not to mention that coasting in Neutral is a traffic code violation in some states (but how it would ever be enforced is beyond me).

 

I think going above 62 mph in EV mode in Neutral is an extreme/rare case. Most people wouldn't have that kind of hill to roll down to gain that kind of speed. Even if they do, it is easy to control the speed with the brake pads.

62 mph to a stop would regen a few EV miles so if someone has that kind of downhill, it would be better to partially charge it.

 

I'm confused, I thought the whole point of neutral was that it disengaged the wheels from the psd. How could you ever overspeed anything?

 

i think they mean if you shift back into drive.

 

Oh, right, so you'd want to be below 62 when shifting back. Since this is supposedly taking place in a residential neighborhood, I certainly hope no one is driving that fast to begin with.

 

Is it possible to mechanically disengage the three gears in the PSD? I thought that Neutral was just a control state telling the control unit to not attempt to manage the power flow. There is no clutch mechanism to mechanically disengage the gear in the PSD that is attached to the drive shaft of the ICE, is there? I thought that the "magic" of the PSD was how the motor-generators removed the need for a transmission or clutch.

 

so you can damage it at high speeds even in neutral?

 

I had been under the impression that neutral was supposed to be a true neutral by law. Anyone else?

 

CharlesH is right. PSD is always connected to the wheels. It never disengage.

So yes, you can overspeed the MG1 if you go over 62 mph in Neutral and the ICE does not rev up.

 

huh.