MPG display updated?

Funny, I was just going to post something on this and saw your new thread. I have a V, 2 months old and 2200 miles. Average MPG for those total miles (from delivery) 48.2. Built in May, delivered June 13.

My previous MPG 'high' as noted on the MID bar graph was 49.6 for 222 miles. This morning I saw my average was 50.1 over 209 miles and thought I'd fill up and reset the odometer to get a new high.

So, stopped at my normal station just now and filled up - same pump as last fillup, similar temp, and stopped at the first click. Bottom line - 4.11 gallons . So my MID read 50.1 and my 'true' miles to gas - calculations are 50.9.

I was always assuming, from posts here, that actual MPG was a bit lower compared to the MID posted numbers. At least this cycle, mine was right-on.... BTW, regular gas here (Orlando FL area) $2.55 gallon

 

Mine is only two weeks old but the display and the calculated mileage are very close. Calculated is 48.152 and the computer showed 48.5.

 

The only thing I can say, is that I hope Toyota fixes this discrepancy soon.

Granted, this discrepancy may not be affecting everyone equally which based on my observations of local group of 6 units (mine included), seems to affect those who pursue higher MPGs more than those who do not.

As an example, if my displayed FE ranks in the 3.3 L/100km or lower (71 MPG US or higher) then I can expect a calculated hit of at least 0.4-0.5 L/100km (6-7 MPG US).

Despite, being a significant improvement in so many areas over the Gen-II Prius, this displayed FE deception and overall lower FE potential than the Gen II Prius is seriously taking the shine out of my 2010 Prius.
It kind of reminds me of the 2010 Insight blunder -- improve some things and devolve others.

Cheers;

MSantos

 

Me too! Amen.

 

Aren't these two separate issues? How do you conclude that the gen III has "overall lower FE potential than the Gen II"?

 

Simple.

With a Gen 2, I am able to easily extract 70-90 MPG on a typical suburban commute. On a Gen 3 it is literally impossible. Even the lower speed IGN 13-16 was not only easier to lock in, but also yielded far better results on the Gen 2. Don't even mention WS on the Gen 3.

On the Highway, things get even worse for the Gen 3 Prius as not even the acclaimed SHM mode (now on IGN 19-22) delivers as much as we expected -- even when the speeds are kept at or below 50 MPH. In this area, the GEN 2 has a higher FE potential.

I am not alone in my observations and I sadly share the same assessment with other hypermilers. The displayed discrepancy just confirms the disappointment beyond redemption.

Please note the use of the word "Potential" as most folks could not care less about the difference between 90g and 60g of CO2/km.

Cheers;

MSantos

 

I am a newbie and don't know enough to take sides. You are the third person in this thread to make the same statement but you don't provide data or links to threads/sites where specifics are discussed. Therefore it is not clear to me. I find this frustrating. I have looked at hypermiling sites looking for this info. I am just trying to learn.

What specifically are you and others seeing in the Gen III that disappoints you?

At least Diamond Larry gives some figures. When you are getting 76 mpg in your '07, what state is the HSD in that you can't create in the Gen III?

 

Here is a Pri III review from CleanMPG that goes into some detail.

 

I did read that review. Here is the gist of what they say:

" Though still capable of 100+ MPG in a standard P&G routine, average speeds needed to achieve the numbers above are cause for concern. Temps in the low 60’s were slightly problematic as this was a brand new vehicle with placard pressure, but it did not have the same 100+ MPG “pop” that the previous generation Prius has at any speed between 22 and 37 mph. Forced Charging appeared to stop at 6 bars of SoC during a warm-up period and it did match the previous generation Prius in allowing moving to 7/8 bars at will.

At this point, if I was entering a max FE competition today, I would ask for the Prius-II. The new generation may well be more capable but I need more time in a prepped Prius-III to determine its full potential."

I would like a follow up with more experience and details and explanations. I haven't been able to find that. If it does exist, I'm just looking for a link to find it.

They do say that highway driving "is an area where the Prius has improved for the average driver just exactly as the EPA numbers indicate."

I know that this is off topic of the display mpg error, so I'll ask more specific questions about hypermiling the 2010 elsewhere.

 

Hi royrose:

We will have a detailed Gen 3 Prius review coming up... stay tuned.

Cheers;

MSantos

 

Excellent, I'll keep my eye out and look forward to it.

I'll admit I contributed to the sidetracking.

As far as the MPG display, I'm not as optimistic as you are. I'm afraid that you are engaging in wishful thinking.

I am finally getting my Prius IV six days from now! I'll track the real vs displayed mpg and report back.

 

There's a whole thread on calculated mpg vs. the trip display mpg on the gen III. So far, I'm afraid most people are reporting quite a bit of discrepancy between the two -- generally, the display is 2 or 3 mpg higher than the calculated mileage.

I've filled up twice since I bought mine. For the first one, my calculated mpg was actually slightly higher than the display. For the second one, it was 2 mpg lower, consistent with what others are reporting. However, it's still much too early to judge. And we do have to keep in mind that all Gen III Priuses are still pretty young, so few people will have filled up that many times to provide really meaningful data.

 

I have a case # from when I called them after Hybridfest. It's been a month now since she said the engineers were looking at it. I will call them tomorrow.

 

How did EPA compute the 50mpg figure?

 

See also How Vehicles Are Tested