Prius-II OEM PHEV-6 caught in the wild

[brick]

I should clarify: When I said "battery" I really meant "plug-in battery." I'd like to keep the battery that's already there.

[mparrish]

Originally Posted by ksstathead

Interesting perspective. I need the battery for in-town driving. Would highway mileage be better if some or all of the extra battery could be removed for longer and/or higher speed freeway trips? There is still conversion loss to get power in the pack...

Curious if anyone cares to guess what the city and highway EPA ratings for this -6 configuration might be. EPA won't be hypermiling or plugging in to re-charge, so won't the highway mileage be slightly less than Prius-II due to weight, but maybe they get a little more out of the city tests? Steady-state freeway mileage has to go down, right?

Also, what sort of hypermiled city and highway mileage might this setup allow? 100+ in town? 80+ highway at 62mph and below?

My thoughts were the same as Brick's initially. Just give me that glide. But then I started thinking about all of those Prius purchasers who get on Priuschat and say "I only get 35mpg, and yes all my driving is short trips". A mere PHEV-6 might not end gas entirely for most commutes, but boy will it help the short trip syndrome a lot.

My guess is that highway EPA would be better at all speeds, and not worse at any. If I were designing the thing, I would leave the "mimic" exactly where it is (around 65% SOC currently, much lower with two packs), and program the computer to bleed (assist) any excess charge until that mimic level is reached. What that means in practical terms is that you'd have two full packs in the morning, you'd get on the highway, and you'd have 6 miles of grid-generated pack assist of the ICE on the highway, which would get you iMPG in Insight territory for a while.

When you reached the current mimic level, assist would end and the computer would maintain that level on the highway (65% SOC) with the arrows flashing back and forth between assist and powering up the pack. Then iMPG would fall back down to more Prius like levels.

If you didn't keep the mimic where it currently is, then a long highway trip without an overnight grid charge would fill, and fill, and fill, and fill up that pack. And that's no good. I don't want gas filling up two packs. I'd rather fill it up from the grid when I get to my destination.

If this doesn't make a lick of sense, let me know and I'll take another stab at it.

[ksstathead]

Thanks mparrish.

Won't the EPA conduct it's tests such that SoC is the same at beginning and end? If so, where does the mpg bump come from in steady mph above 62? Or even steady mph below 62? I know the folks here will drive smarter, but where will the EPA get better highway results? We know the extra weight pulls it down, but where is the offset for them? Certainly they get some back from regen at exits and stops, but I'm thinking that can't offset the extra weight in longer trips.

Also, wouldn't you want to have the pack just get enough recharge to assist on climbs and to run AC and other accessories in steady state highway driving? (I'm ignoring the initial 6-10 miles of pack benefit from charging in the garage, like I'm starting from the hotel parking lot on vacation.) I'd think you want the gas going straight to the highway to minimize conversion losses.

I just think the world at large may yawn because it cannot beat the P-II under highway cruise control. (I'll buy mine before they "get it.") But man, in town and stop and go this thing ought to be spectacular.

[mparrish]

ksstathead, these are great questions. And the most important thing for me to point out is that I don't know the answers . I honestly don't know much about the details of the EPA tests themselves. I bet others here do. But it's worthwhile and fun to talk them out.

Originally Posted by ksstathead

Won't the EPA conduct it's tests such that SoC is the same at beginning and end? If so, where does the mpg bump come from in steady mph above 62? Or even steady mph below 62? I know the folks here will drive smarter, but where will the EPA get better highway results? We know the extra weight pulls it down, but where is the offset for them? Certainly they get some back from regen at exits and stops, but I'm thinking that can't offset the extra weight in longer trips.

You are most likely right. If you bought this plug-in Prius and never plugged it in, your highway MPG at any speed would be slightly lower because of additional weight. It leads to all kinda of interesting questions. How does the EPA account for a second, additional fuel source that is both cheaper and optional? Do they publish two sets of ratings? One assuming no use of the optional source, and one assuming daily use? That seems like a good "truth in advertising" solution to me. So maybe the Prius on the highway goes from 45mpg to 43mpg (no charge) / 60mpg (daily charge) assuming a fixed number of highway miles driven. Also, charging ain't free. Should daily use kWh be converted into a mpg-equivalent? I'd say yes. Either that, or your new EPA ratings are 43mpg/0mpkWh (no charge) / 43mpg/17mpkWh or something. Now my head hurts. Those EPA ratings are completely unhelpful to the typical consumer.

Originally Posted by ksstathead

Also, wouldn't you want to have the pack just get enough recharge to assist on climbs and to run AC and other accessories in steady state highway driving? (I'm ignoring the initial 6-10 miles of pack benefit from charging in the garage, like I'm starting from the hotel parking lot on vacation.) I'd think you want the gas going straight to the highway to minimize conversion losses.

Yes. Once the initial 6-10 miles of grid charging is exhausted, I'm assuming the plug-in would operate just as any Prius today...maintaining (bleeding & charging) a steady SOC as needed for climbs and electronics and such.

Originally Posted by ksstathead

I just think the world at large may yawn because it cannot beat the P-II under highway cruise control. (I'll buy mine before they "get it.") But man, in town and stop and go this thing ought to be spectacular.

I think in the end the EPA has to at least publicize a likely improvement in "miles per fuel cost" in some easy to understand manner assuming one plug-in per day and a typical number of highway miles driven. That may not be all that should be publicized, and I bet there's a lot of debate how it's done. But I kinda like converting kWh to an mpg-equivalent and then advertising "60mpg-equivalent highway assuming one full daily charge". For the EPA to not take it into account seems almost deceitful.

Yeah, she would be absolutely awesome in the city. At the same time though, as a hypermiler it's the highway that has me excited about these developments. Gliding up to 62mph will of course kick butt. But in addition to that most of us have our 10 mile highway trips from time to time and like many I know I can stretch that 6 miles of charge out to maintain Insight-like highway performance for most of my highway driving needs within the city.

[sup'd]

Originally Posted by mparrish

If you didn't keep the mimic where it currently is, then a long highway trip without an overnight grid charge would fill, and fill, and fill, and fill up that pack. And that's no good. I don't want gas filling up two packs. I'd rather fill it up from the grid when I get to my destination.

My thought would be you would change the 40-80% range to the lower bound of the 2 pack SoC range + 20% when the pack is depleted.

So if the double pack SoC range is 10-90%, once the pack reached 10% it goes into normal operation between 10-30%, trying to hold ~22% until you plug in. Or have it go into normal at 22%. I think we're saying the same thing, but I'm thinking a lower mimic level with a smaller range.

[xcel]

Hi Ron3Kl:

___2009 is when the Prius-III w/ NiMH’s arrive. It will have all the capabilities of the Prius-II PHEV-6 minus the plug-in and larger pack. 2010 comes a Li-Ion HEV. 2010/2011 comes the plug-in. Engineers and managers on the ground hinted at complete swap ability between the NiMH’s and later Li-Ion’s but like anything else, plans do in fact change.

___Bestmapman, only if you can get a hold of that flash and SW upgrades to the new screen additions by all appearances

___JimboK, PHEV-6 means 6 miles or AER on the EPA’s city/highway tests. Real world for us, a lot more

___Ksstathead, the warm-up hit for those really short commutes disappear altogether! If your speeds are under 34 mph, any conversion would allow no fuel use up to the packs cap. About the highway FE. Because you can now glide from 62 on down, you bet their would be a benefit on the highway. You have to come to a stop or are coming down hill at some point and when you do, the newly added capability would really help. Add the ability to really P&G at highway speeds and this thing could really kick @$$!

___WRT the FE tests, both Toyota and Honda are way ahead of most when it comes to the EPA PHEV and FCV testing and are helping write the FE rules for a future PHEV mpg equivalent.

___Sup’d, it appears that there is more range of SoC given the miles of AER added with a doubling of the pack. Once the bottom has been reached, it does everything a standard Prius is capable of. I am not sure of exact SoC but was simply told it will act similar to a regular Prius once the pack has been depleted. I doubt 10% on the boom is the target but I suspect maybe 25 to 30% is?

___Mparrish, yup

___Ed, if there is ever a Group Buy capability, you bet

___Good Luck

___Wayne

[ksstathead]

Originally Posted by xcel

Hi Ron3Kl:

___2009 is when the Prius-III w/ NiMH’s arrive. It will have all the capabilities of the Prius-II PHEV-6 minus the plug-in and larger pack. 2010 comes a Li-Ion HEV. 2010/2011 comes the plug-in.

Wayne,

Thanks for the update. So what does the 2009 Prius-III add? The extra MFD displays? An EV button? (It's not PHEV and has the same pack...) EDIT: AHHH! HIGH SPEED GLIDE, now I get it...

thx,
ksstathead

[xcel]

Hi Ksstathead:

___The engineers and managers that were at the Press-Preview drive were are under very strict confidentiality so nothing exact was given out. Some of the individuals hinted that the 62 mph EV (I prefer to call it the glide capability ) will be standard fare in the 09 Prius-III. They would not even hint if the updated display will be available or not Everything else is just a few paraphrases of what was previously posted.

___I would suspect the EV button will make it given it is now on the new 08 HiHy. If they got that vehicle past the EPA, I see no reason why the PHEV version minus the P would not make it as driven?

___Having said all of that, the PHEV-6 makes the Prius-II a completely different animal in terms of what any of us could do with it. I believe the range is way too short for the everyday consumer and who would not want a 20 – 40 miles range but with a < $1.5K OEM upgrade, who here would not purchase this short range plug-in w/ the seriously upgraded capability today if it were available on the lot

___With Toyota’s recent announcement of up to 400 of these babies hitting American roads (for testing and acceptance purposes only ) I have a feeling Toyota wants that ECU and MFD programming to make it into the wild so as to make the American PHEV conversions worth so much more then they are today. We are talking about real world speed no fuel use PHEV’s when this thing gets out and that in and of itself is enough to say, “I am buying a Prius” for many!

___I should have done this in the first post but I want to personally thank Bill Reinert for making the Press-Drive possible for Blake and I. It is one thing to speak with the engineers and such but another to be speaking with a media person and turn around for a 5-minute conversation with one of my real-life heroes working deep inside of Toyota! He is just as funny and engaging as he is in film and was one of the many highlights we experienced at the NAIAS 2008

___Good Luck

___Wayne

[Skwyre7]

Wayne,

Any ideas on how I could "volunteer" to be one of the 400 testers?

[ksstathead]

What Skwyre7 said!

So these 09 Prii would be out this fall as an 09 model?