Real World MPG Numbers

On my 2012 Prius v the MPG for total miles driven would reset when I pressed update on the PAST HISTORY screen (PAST HISTORY screen attached below.)
View attachment 104978

Could this explain the bouncing MPG for total miles driven?

 

Hey new owners, please consider putting your mileage up on:

Fuel Economy​

Fuelly.com com is also good but the EPA site gets a lot of visitors who aren't us. <GRINS>

Bob Wilson

 

Same in Spritmonitor.de, I saw yesterday, there is only one 4gen Prius registered...

 

I'm already on there.


iPhone ?

 

Joined too...averaging 54.1 mph (first fill) with the P4 in hilly conditions and 40-50 F weather in Portland, OR. Best was ~70 mpg on a 30 mile round trip (mostly freeway), and it seems to be settling down into the high 50s - 60s in the past week or so.

 

I have seen many comments about the MFD optimism, but has anyone ever checked the odometer accuracy? The testing the Wayne Gerdes did on a prototype Two Eco has been mentioned a few times here with the take away being that the MFD was dead on. But if you look at his calculations, it shows that the odometer under reported by 2.1% while the MFD over reported by 1.6% IIRC. The differences largely balanced out to what has been reported as dead on.

I noticed this also on my production Two Eco as well. The commute that I have been making in my Gen 2 and Gen 3 for 9 years always ended up around 130 miles round trip for 9 years. But now with the Gen 4, it is 125.0 miles.

Wayne Gerdes used a garmin to check distance. Since I don't have a garmin, I used Google maps to painstakingly plot the round trip commute. Google maps says it is 128.1 miles or 2.5% higher than what my odometer shows. I wonder if Fuelly lets you compensate for odometer inaccuracy of do you just have to calculate and add the miles manually?

Anyway, that result is with the Bridgestone Ecopia 422 plus 195/65/15 89S. What could you expect from the 17's? Based on the N/V ratio data in the EPA test files, the 17's are 20.1 and the 15's are 20.0. So 20.0/20.1= 97.5%. So compared to the 15's, the 17's register 2.5% fewer miles. Theoretically, that would make the ODO dead on with 17's.

It would be interesting if others reported on odometer accuracy as well. Just to verity my results.

 

On a British website, they reported that in their government's certifications, the 17 inch wheels generate 83grams/kilometer of CO2 vs 70 for the 15 inchers. Toyota offers the 15 inches on all trim levels in order to bypass some sort of regulation or fee to drive said vehicle in London.
My suspicion is that here in the USA Toyota certified a mix of both tire types to get the 52mpg rating. They certified the 2 ECO with 15 inch tires and higher specified tire pressure to get the 56 overall mpg.

 

And what is there is simple the purchase price of the car he has yet to fuel up once...
( Benzinverbrauch: Toyota - Prius - Prius 1.8 Hybrid Dynamic - Spritmonitor.de )

 

First refuel.

Drove 586 miles, then fuel light came on. Put in 10.3 gallons.

Dashboard display says I was averaging 60.5 mpg.

My hand calculation says I got 56.8 mpg.

So I will assume the dash display overstates the mileage by about 4 mpg.

That's fine. 56 is wonderful.

I pretty much just drive it like a regular car.

 

Which car? Eco or regular?

 

inferno, I have the regular 2016 Three model. I chose the Three model because I wanted a spare tire, and the new Lithium-Ion battery.

I drive in "Eco" mode and "Normal" mode. Don't notice much difference.

I haven't tried "Power" yet. Don't think I will need it.

I'm perfectly happy with 56 mpg. My '05 Camry SE with the V6 engine was only getting about 17 mpg around the city.

 

If you have 15" wheels, your odometer is probably under reporting by about 2%. So you actually drove 597 miles and you are at 58 MPG. Bonus!

 

krousdb, that's interesting. How did you come about that information? Did you see test data somewhere?

I don't trust the fuel mileage figure that is shown after making short trips; 25, 50, 100 miles. I was in the 80s after some of those short drives!

I wanted to see the mpg after going through a full tank. And I got 56. After driving that gas-guzzling Camry for 11 years, I'd be happy with just getting 40 mpg!

(Yes, my Three model comes with the 15" wheels, same as your Two. And I have Toyo tires.)

 

I have verified the Odometer discrepancy using google maps (three times) and others have used a Gps to get similar results. Those that have the 17" wheels should be over reporting by about 0.5 %.

 

I drove around this morning and kept the car 100% in the "Normal" mode. It actually drives easier (compared to "Eco") performs better, and the gas mileage didn't suffer at all.

No more "Eco" for me. I'll leave that to all you old Hippies.

 

Funnily enough the EPA testers had the largest error using 'Eco' versus normal or power.

Bob Wilson

 

I like this combo, Normal mode (city) Eco mode (freeway) works great.

 

So far, three fill-ups in my Two Eco. The MFD has been 1.5%, 2.4%, and 1.1% higher than the good ol' odometer, pencil, paper, and calculator method.