Is the ICE kicking on in EV mode?

Yes, mine kicks in for about 1 minute. I think it is just circulating fluids in the engine, etc. and then it shuts down.

 

The ICE will come on when:

1. The amount of acceleration you "request" sends the HSI indicator into the PWR section

2. Turn on the heater

3. The amount of regeneration is too much for the battery to "handle" (I've read this is the same for the no-plug Prius)

4. From the manual, if you drive more than 150 miles (or something like that) without starting the ICE, then it will start to circulate fluids and what not. I have not experienced this.

I'd say the only time it kicks on unexpectedly is #3, since you can't really see your SoC unless you have a Scangauge or Torque running. This is exactly what has happened to me in the past couple days.

I leave the house with 85.1% SoC, drive out of the 'hood, get to about 83.1-82.9% SoC or so. Then on a short, downhill descent, I regen enough to get it back to 83.9%.. after a few seconds at 83.9%, the ICE turns on (leading me to believe the threshold is 84% SoC).

I guess it would be nice to be able to floor the car in EV only.. not having to worry about triggering the ICE.. maybe like a Super EV mode that you can select like PWR. Although at the same time, I can see why they didnt include something like that also. If you floor it, generally speaking, you need to move (maybe out of harms way). So since the ICE is there, it should help out with your acceleration when the need arises.

 

The EV HSI is different (well, behaves different and looks a little different) than the regular HV HSI display. First, it doesnt have that middle line. Second, the same amount of throttle input will appear differently on the EV HSI and the HV HSI.

What I mean is, I'll be in EV and I'm about to run out of EV range. Once I do, it switches to HV. However, it feels like the car is still running on EV only. You can hear the engine running, but I guess if the power demand isnt there, it wont "help" unless it needs to (not until it warms up, at least).

So, I'm driving, about to run out of EV, the EV HSI indicator is around the middle, when the switchover happens, I dont change the amount of throttle input, but the HV HSI indicator shows me in the PWR section (this is just in normal HV, no Eco or Power mode).

You probably didnt see them, but I made a couple videos a few weeks ago when I first got my car. The first video, you can see I triggered the ICE (watch the white EV car icon, once it goes out, the ICE is on). In the second video, I was a bit more conservative and kept it away from the PWR section and it stayed in EV up to 50mph. I only did it up to 50mph because on my morning commute, I dont think there's any stretch where I could get it up to 60 before coming to a stoplight.

http://priuschat.com/forums/toyota-...mph-electric-vehicle-acceleration-videos.html

 

That ability has been "dissed" quite often in Volt threads.

 

I think whether the amount of EV acceleration is enough really depends on your area and the speed limit. Most people, it seems, like to accelerate fairly briskly up to a certain speed and then back off on the throttle (that certain speed may be a quick 0-20 or 0-40, for example). When driving the PiP in EV, the acceleration is fairly linear, so depending on who is behind you, they may feel you're not accelerating as quickly as they would expect, even though ultimately, you will be traveling at the same speed or faster.

I also feel as though morning traffic isnt as fast as evening traffic (I guess everyone is in a hurry to get home, but not so much getting to work). In my area, there are a few roads that have posted speed limits of 55MPH. There are very few roads with speed limits less than 50. Closer to work, it is more like 40-45MPH.

 

My daily experience is the opposite and it gets worse the closer it is to 8 a.m.

 

Yeah, I'm sure its something people will talk "stuff" about. Even with the ICE, the Prius Plug-In is no match for a Volt in a drag race, so there's not much to say, I guess.

However, I would rather burn gas for "harder" acceleration than use electricity. I dont have any numbers to back it up, but I imagine hard EV acceleration "burns" through a lot of EV range. Seems like a waste since it took so long to "put there" (in the battery), relatively speaking.

 

I get to work at 9.. maybe thats the difference

 

When I had a demo unit for a week, it happened twice, that for no apparent reason, Prius started the ICE. Both times I had plenty of EV range.
The first time I was standing in front of a traffic light. Even stranger was the fact, that when consumption bar dropped to 0 liters/100km, I could feel the ICE running (vibrations). After 10 seconds the ICE then shut down.
The second time, the Prius was also standing still. I sat on the passenger seat as I gave I test ride to a Prius Gen2 driver. He switched to R and the ICE started for no apparent reason.

 

Your choice. Given you have a small battery and will likely use the ICE anyhow (for speed) its reasonable to use it for acceleration. It does not take that "long" to put it there, I charge overnight and as long as its done when I go to work, its no longer. I prefer to go for weeks without using any gas, on my 36-mile commute+errands. Can still accelerate hard when i need it. Maybe I'll go measure the % battery a 0-60 takes for different levels of acceleration.

Edit: Did measurements in my Volt on the way home. 4 different 0-60mph acceleration test, with torque timing it and measuring battery impact.

First was uphill on the highway onramp 10.1seconds using change in battery level (0=empty 100=full) was 2.7%. Second was on a slight uphill but more level after a light, 9.1 seconds using 2.6%. Third was very level, straight 8.9sec, 2.4%. Four was pretty level but had a turn in it (and a car approaching a T in the road, probably distracted me so it was 10.1 and 2.5%. All in all It was pretty much my normal trip home. The trip is 36miles, yesterday I had 9 miles of range left. Today I had 5 left, so the 4 agressive 0-60's ate 4 miles of range.

 

Do they include regen to slow back down?

Say average is 2.5% consumption in 10 seconds, that's 400 Wh (16kWh*0.025). To charge it back with the standard charger, it would take 17 mins (~1,000 seconds). By a factor of 100!

If you used some gas for acceleration, you'll have more EV range to cruise (instead of wasting it on acceleration).

Here we are at again, using gas for power vs. range. What's the difference? Is using gas for range better than using gas for power?

Using gas for high power increases the battery EV range. Using the battery for acceleration reduces the EV range and you'll end up using gas to get more range.

The first strategy reduces weight, requires smaller battery, costs less and gain more interior space. The second strategy is really for EV purist that is not OK with using gas for power but OK to get more range... for some reason.

 

The difference is if you will need to burn gas at all. If your trip is short enough that you won't need to burn gas for range, avoiding using it for power saves more oil consumption.

If I knew I was going 100 miles so would burn gas anyway, I'd want to use gas for power to get more EV range, If I knew I was going 20 miles and wouldn't burn any gas anyway I'd prefer to keep the ICE off.

Like someone else suggested I wish there was a user select-able switch to set your preference based on your knowledge of your drive.

 

I have a user selectable option. I use the LEAF when i don't want to burn gas and I use the 2007 prius when I need to.

Actually, one reason i got the LEAF for my commuting is my "20 mile" days - something that I do regularly - would be pure EV. the PiP would have been hit or miss on whether I could hypermile the day all in EV. (I suppose a Volt would have been a good fit for my driving pattern, but I don't fit in it and it cost more money....)


That being said, I'm scheduled to test drive a PiP this saturday. I suppose if my wife really likes it (to the point where she doesn't mind that we wouldn't get the full 2500 tax credit) we might replace the 07 prius... If we do get the PiP, I'm sure I'll be wanting a more user select-able mode switch

 

is this tax credit different than the credit for the leaf? because the leaf credit is applicable to AMT, if that's what you're talking about.

 

Slow down? what is that?

I measured the battery difference just after I hit 60.

For comparison I measured slower 0-60 on the way in. For 13.6 and 13.7, slightly downhill, it was 2.1% of battery. For 22.5 seconds for 0-60 slightly down hill it was 1.9% of battery.

All percentages are of usable battery not total (so 13kw)

So the real delta for agressive acceleration vs 22 second (pokey even for a prius) is about .6% of usable battery of 13kw (from wall) or 13kWh *.005 about 65-75 Wh.

Looking at the delta in terms of range, 40*.005 = 0.2 miles. Not worth the pollution/gas to save such a small amount of range.

A user should be sizing their battery pack so the normal day is EV so the added range does not matter on those days. On days I have to run errands I avoid jackrabbit starts and drive more efficiently.

A EV purist that does not look at their other needs/usage (beyond the battery range they take a rental or other ICE), is not so pure. If I had a Leaf then since August I would have used 50+ gallons of gas (> 2x) because I'd have to take my wifes car on the longer trips).

Reducing batteries reduces range and overall MPG -- it uses more gas but costs a little more. The Voltstats.net data shows 121MPG over nearly 4million real user miles. You can try to say using gas for power saves gas, but clearly it does not. Averages being posted for PiPs are mid 70s overall MPG (some higher, many lower. And like for the volt, the users with the highest milage have the lowest averages).

The only car in which I could have used less gas was the roadster. And in that sense the Volt, allows me to use the ICE to reduce costs. 30K net vs 100K net.