New PiP Owners...More data please!!!

All this info re: storing and releasing more "free" energy is totally unexpected and extremely exciting.

Although I don't doubt the posters' anecdotal experience, is there any scientific data or testing to back it up? That (for a lot of people) could be the tipping point between buying a PIP and just waiting for the next big thing.

 

Well you can look at the EPA testing, which is relatively controlled and did not provide a higher overall combined rating in HV mode.
Real data in this thread
http://priuschat.com/forums/toyota-prius-plug-in/106610-pip-mpg-spreadsheet.html
and the associated spreadsheet, show about 50mpg. (Note the total is skewed by a funky entries for crewdog and Devprius, that are dividing by the last tank rather than total gallons).

Comments such as its li-ion vs NiMH have no scientific basis, as the battery chemistry does not play into it. The ability to supply more instantaneous current could (but there's much more to that than just chemistry). The batterie's ability to store more excess power easily could have an impact on some commutes.. anyone that would end up using engine braking (a-la B mode) because the hybrid battery was full, would do better with a Prius, but that must be a small fraction.

It is, however, possible that the added battery allows those people with good driving habits to do better, and those with more agressive habits, to do equally worse. When it comes to estimates I think the bigger the battery the greater the variance in measurements as it amplifies different things for different people.

So while we hear some good stories here, neither the data on the PC spreadsheet, nor the EPA testing, seem to suggest a statistically significant difference overall. Data at the spreadsheet is still small, but HV estimates are pretty consistent.

 

Fuel up data this morning:
7.573 gal to first click
2 pips on fuel gauge, dte 78 mi
733.4 mi this tank:
99 indicated mpg, 96.84 calc mpg
41% EV, 59% HV
61 kwh on car, 71.29 kwh on kill-a-watt
fuel saved by charge 5.1 gal

had some more freeway and slightly more aggressive driving this tank. I also noticed the slight drop in mpg when it's raining.

Dang, this car is just incredible.....

added info to spreadsheet.

 

Thanks.. you posts in the spreadsheet are a bit confusing.. one in april said cumulative this is not?

 

That misses the point.

Remember all the worry about MPG taking a hit from added weight of the bigger battery-pack and extra components?

Clearly, that didn't hit didn't occur.

 

Sorry about the confusion.

In April I did not reset the trip meter for all the displays as I should have.

This tank I had reset, so the posted results are for the current tank.

If it helps, I can just delete the data from April that was for lifetime.

Bill

 

It does not miss the point, if you read the post you'll see I was replying to a particular post asking if the HV mode of the PiP had scientific evidence supporting greater MPG. Many people are posting they are getting much better HV mode milage, and some was curious if it was real or perception.


And I don't recall the worry about weight.. and would not have given it any concern because weight is not near a much of an issue for a vehicle with regen braking. You loose a little on take off/uphill but gain much of it back on stopping/downhill.

 

What funky entries do I have that need to be corrected? Or am I entering data in an incorrect manner?

 

My bad devprius.. it was netsirkdmb.. I miss read the line. There is wierd alignment issue in my browser.

 

Look at the entire history, then the big picture.

279 MPG from my 35.7 mile commute today, which compliments the balance of other purchase priorities quite well.

That's the point.

 

No prob. My entries will always be on a per-tank basis.

 

Pretty good for a Pip.. what was that 2 or three recharges?

But as many have shown, for many people the PiP will be an acceptable and efficient choice.


With respect to the history, there is no point at looking how others had poor expectations and mis-guessed the issue of weight. Those who did may revisit to learn from their errors. But I've steadily arguing that weight is a 2nd or 3rd order effect (especially with folks that like to throw out terms like weigh as much as a SUV)

 

There are only 2 drive segments, a third would be impossible.

As for the history, we've watched it repeat. Not being explicit & proactive would be allowing it to happen again.

 

It's too subtle and there are far too many variables to get anything blatant. That simply isn't going to happen. Don't expect quantitative & repeatable results.

However, there are a few small things that do make the it difficult deny. The one that jumps out at me is how quickly the engine shuts off.

My PHV definitely kicks into electric-only driving faster than my 2010 did. Of course, that could be true for the regular 2012 model too.

Being a moving target makes comparisons even more complex.

 

We're participating in this thread in order to provide and share data. Our conclusions may be wrong, but our data aren't.

Did the EPA actually perform gas MPG tests on the PiP?

 

I was not questioning your data, just the postulated reasons it might be doing better. I'm here reading to learn.. I was simply answering a question by M8s post (http://priuschat.com/forums/toyota-...p-owners-more-data-please-39.html#post1556338) asking if there was any scientific basis for better milage.

And as far as I know the EPA did not directly test the Plug-in Prius, Toyota did and reported the data using the EPA processes. But all companies know that the EPA may retest to verify claims.

The most plausible reason is good drivers, not the actual tech. If Toyota knew how to get better highway milage in CS mode, they would have done it as that would be a strong selling point. And they know way more about the car than all of us combined.

But I'll say again

 

True, the PiP is a hypermiler's dream. My PiP data is still pretty new, but it's very useful, because I drive an 80-mile r/t commute five days a week, an I've run that in my 2010 Prius for two full years which I've logged on Fuelly:
http://www.fuelly.com/driver/rebound/prius

And now I'm logging the same commute with the PiP on Fuelly:
http://www.fuelly.com/driver/rebound/prius-plugin

My first fill up of 53 MPG was the 400 mile drive from LA to SF, without a charge. And the second fill up was before I had the EVSE installed, so I was often without a morning charge. The very best tank mileage I ever got with the Prius was 58 MPG (LOTS of pulse and glide), while with the PiP it was 75. That's a big difference.

We could noodle around with the math and subtract the EV miles, but I'm pretty sure net mileage would be higher. This car has more glide available. If you use that 11 mile charge just in the ordinary Prius Glide zone, it will go on and on and on. I drove carefully to get my 75 MPG tank, but I am by no means a fanatical hypermiler.

My problem now is that I have the green stickers. So now my car drives in the fast lane, and it reduces mileage. But I'm not going to pulse/glide in bumper-to-bumper just for fun.

 

I hope there is factual support for your experience. I can think of several reasons why this may be the case.

For example, I bet the software that controls the Hybrid Synergy Drive (HSD) systems is significantly different between a normal Prius and a PIP.

- The PIP is almost certainly programmed to favor EV much more than a standard Prius, using EV for a much longer time and over a much larger range of speeds.

- Given the additional storage capacity of the battery, the PIP may be programmed to regenerate more aggressively so as to store larger quantities of "free" electricity. For all I know, its MGs are larger and more powerful (or the same size but less restrained) for this purpose.

- Whereas the standard Prius might use the ICE to go up a hill and regenerate going back down, the PIP could use EV mode going up and the net gas usage would be reduced to zero. When experienced repeatedly over a hilly terrain, that could result in significant savings.

- Once you reach a given speed, say 35 mph, an EV's ability to simply maintain that speed is more precise and efficient than even the most economical ICE;

- Other programming strategies particular to the PIP may be employed that, individually, might give small incrimental mileage improvements but, added together over a longer commute, could add up to significant improvements in fuel usage.

I'm confident the talented and hard-working engineers at Toyota have far exceeded my guesses in the actual PIP HSD programming. If the PIP's economy is what the current owners feel it is and more, there may be a 4th Prius in our future!