My Prius uses the battery more than the Honda hybrid (civic)

Please, not the "Full Battery" torture!!

 

Sonata/Optima Hybrid has major issue on transmission failure, mostly under warranty, hopefully they have long term fix instead of software update only.

 

I'm still waiting to make it I guess. My commute is almost 8 undulating miles. With only an initial startup ICE running I can make it home almost completely on the battery with no "red arrow" flowing. I regen down hills and at stops, glide a little to make it up and over the crests with less than a 10 mph difference. I rarely go over 45 mph and staying in as constant an "EV" mode as I can, consistently achieve between 75 and 99.9 mpg. On the display when I reach my destination. Pulse and Glide for me lasted about a week. Here's my first thing in the morning where is stop for coffee from being dead cold from the day before. I get this all the time. My first daily 2.2 miles.

 

I have to disagree. The regeneration systems (according to Toyota engineering) is responsible for about 1/3 of the efficiencies in the Prius. The Synergy firmware is responsible for another 1/3 and the engine for only 15%. I assume that is why the regen systems are not taken into account in the Ford quote. They would not emphasize something they cannot provide.

 

I think many people are merely puzzled why you chose to own a car that you are constantly complaining about and putting down

As to your comment about the Prius wasting a lot of energy using the battery, yes and no. The stock algorithm is extremely effective at compensating for the inefficiencies of the average driver and average driving conditions. After several years of conversations, my co-worker bought his first Prius (and first hybrid) last fall. He's always been a fairly efficient driver, but not a hypermiler by any means. From day 1 he's been averaging 55-60mpg per tank by just driving how he normally does on his ~35 mile RT daily urban mixed highway/city commute. With a bit of mild opportunistic pulse and glide he's now in the 60-62mpg per tank range even with temps now over 100 requiring AC use and his continuing to drive ~70mph+ on his freeway extended portion. That's pretty cool.

On the other hand, I do believe that the conventional wisdom that has developed over time on this site and elsewhere says that to drive the Prius as efficiently as possible you have to learn to drive it in a way that uses as little battery power as possible (amongst other tricks to optimize ICE usage). It takes time and research to learn how to do this in the extreme, and adding basic instrumentation such as a scan gauge or torque app helps immensely. For myself I have developed a lot of intuition about how to get the Prius to operate pretty efficiently over the years (with a lot of help from this site), but have never tried to take it to the next level with instrumentation. My last two tank on my Gen 2 were 57 and 58mpg despite a busy life with full time work and 3 young children that doesn't allow for a lot of optimization, so I'm not complaining

Rob

 

Hybrid Synergy Drive (HSD) - Prius Wiki

Funny thing is that everything I have ever read (including what the dealership told me at the sale) says to "just drive the thing". This article pretty much says the same. Everything about the car is supposedly designed NOT to baby it. It's supposed to know more than a human does about being efficient. I like driving it but it's become more of a hobby than a car. My wife's brother has a 2013 Persona and says he gets in the low 40's with it but he's an aggressive, normal Atlanta driver. It is fun but as soon as the novelty wears off and I start driving like I normally do (which is very granny like), and it becomes to much work to get great mpg's, I'll probably trade it for another Civic in a year or so. I got 42+ on the highway and 35+ all day long in the city and I think I paid 18k for an EX with everything on it back in '06 just as the 07's came out.

For all the comparisons to the Civic here, hybrid or not, you really can't beat a conventional Civic or Corolla for that matter to not leave you walking when a battery dies or the software crashes.

 

On these Forums, most of us have no access to the various members themselves, only to their posting histories. While the character may shift with time, old style keeps popping up.

Those figures are from some other hybrid, not from any vintage of Prius engine.

The GenIII 1.8L Prius BSFC commonly posted here shows it operating at nearly constantly efficiency (230 g/kWh or slightly better) from about 75-80 Nm at Idle RPM (roughly 8kW or 10 HP), all the way up to about 4000 RPM, 130-ish Nm (roughly 55 kW or 74 HP), along its programmed operating load line. There is no advantage to switching to EV mode when desired traction power is anywhere within this range. But it may pay to change engine power to charge up a low battery, or drain a bit off a full battery.

At Idle RPM, below torque of about 75 Nm, the GenIII efficiency starts dropping rapidly. When the needed traction power is much less than this (~10 HP), then it likely pays to either run the ICE at a full 10 HP and put the excess power into charging the battery, or shut of the ICE and run EV. And because the battery capacity is fairly limited, this means the ICE will alternate on and off.

In this low power and speed range, drivers can use Pulse & Glide to cut out the generator-battery-electric-motor portion of the energy path and its associated efficiency losses.

GenII figures are different.

 

Are you saying its best to keep the ICE on as much as possible? I drove to work this morning more like I used to drive my Corolla but still keeping the ECO display near the center as much as possible. I was only able to achieve 46.7 when I generally get at least 10mpg better when driving mostly off the battery and using downhills to regen. I am now beginning to wonder if the software flash that was done before I bought it has affected my mpg negatively as many are reporting. I've just been making up for it by driving it like a golf cart.

 

Well, gee, lets see, I wonder why you'd think that?

 

No, using the battery as little as possible is not the same as using the ICE all the time. My understanding is more Gen 2 based, but I believe the fundamentals are the same. When accelerating you can use scan gauge feedback to operate the ICE as close as possible to peak efficiency, and also use as little battery current in or out as possible. This is often at a more robust rate of acceleration than most folks would expect, but not floored. When reaching cruising speed you have two choices depending on traffic and preference. Continue using scan gauge to operate the ICE as efficiently as possible, still with the battery current in/out as low as possible, or preferably go into pulse/glide where pulse is same as acceleration and glide means releasing accelerator to shut off ICE, and then depressing slightly to reduce battery current in/out to zero. When you have to brake, ideally you would realize this as far ahead of time as possible and spend as much of that time gliding as possible.

So the basic idea is to only run the ICE near peak efficiency. This eliminates the need to use significant battery current in/out to improve ICE efficiency, which one could argue is its primary purpose. Any time you are not using the ICE be gliding to allow your momentum to carry the vehicle forward as efficiently as possible.

In the Gen 3 with the HSI I believe you can do some of this without needing the scangauge, though I gather its still helpful for further optimization. On my Gen 2 I've just developed a sense over the years for how to get in the ballpark to each of these modes just using the instantaneous mpg reading, speed, and energy flow display. In an urban environment I've found that selecting the route with the least stops, best timed lights, and reading traffic to find opportunities to use these principles is probably of bigger benefit than implementing them perfectly anyway. The difference for me in a Gen 2 between just driving and employing these ideas as possible is about 56-60mpg vs. 50-52mpg. Note these are tank averages, single trips and specific operating states don't really tell you that much.

Rob

 

I think that's pretty much right on. I have notice the Gen 3 seems quite a bit more likely to toggle in and out of EV at low to moderate speeds. This is essentially implementing a pulse and glide to increase overall efficiency in software without any change in speed. If you are willing/able to tolerate changes in speed a real pulse and glide should still be more efficient, but this could hardly be imposed in software as its certainly not practical, desirable, or safe under all conditions.

Rob

 

Ok? And?

Given that the Prius is larger, more powerful, averages 10-20% better fuel economy by year on fuelly, has outsold the HCH nearly 10:1, and appears to have roughly an order of magnitude lower battery failure rates I'd say whatever Toyota is doing seems to have been a better overall design choice.

 

Please define peak efficiency for the ICE. I try to stay within the ECO range and out if PWR. My drive isn't flat enough to utilize pulse and glide that often. I'll generally pick up speed going down hill, while gliding,to get me up the next grade. If the battery is low I'll just coast instead. I have a gen III and no scanguage.

 

My understanding is that on the HSI peak efficiency is roughly at the top of the eco range / bottom of the pwr range. Hopefully someone with a Gen 3 can confirm.

Maybe this helps visualize, the Prius engine is most efficient around the middle of its power range. It falls off more slowly than most away from this range, but staying in the middle is still the most efficient region.



Rob

 

I'm not sure why it would. Based on the bsfc charts above the 1.8L is more efficient at pretty much any power output.

Rob

 

Thanks Rob. Not having a tach or scanguage, all I have to go by was what was shown in a video I watched from a member. It said 1400 to about 2200 rpm IIRC was the sweet spot which corresponded roughly to above about 1/4 to about 3/4 from the top of the ECO range. I'm waiting for my wireless OBDII "dongle" as we speak for an app I downloaded to my iPhone to try.