Calculated MPG vs. Indicated MPG of the c - Please post your results

If the computer readout was 66 mpg you can safely state
that you obtained over 60 mpg. Based on the computer
for the Prius C being off about 3 mpg (over read).

 

Filled up again today and got 397.1 miles on 8.319 gallons for a calculated 47.73 mpg's. Car indicated 49.9 so about 4% off this time.

 

I am starting to wonder what the Yaris Hybrid, based on the same exact drivetrain, will yield on European roads. It appears that the c is a winner. And is more accurate in reporting the MPG.
BTW: I think most manufacturers are not accurate on their MFD readings on purpose and for cost reasons, moreover 99% of drivers do not calculate the fuel consumption by hand and rely on what reported from the MFD, if they ever look at it. Most drivers go by the amount of money they put in per week/month or trip. Only freaks like us here check to the last decimal way is going on...

 

Hi Pakitt,
You in Germany seems to have more data available than the rest of EU upon the Yaris HSD: by chance, have you come across the weight data of the Yaris HSD, so to compare to Prius C?
I do remember that yaris cx is 0,287 rather than Prius C 0,28 , so i'm expecting something less on highway FE and maybe something more for the rest due to some possible lighter weight. Not only the Yaris is more than 10 cm less than the Prius C in lenght , but also the structure should be lighter due to the slightly less restrictives rules of EuroNCAP crash test.

Edit: Sorry if that sounds a bit OT...

 

Based on a review of the posts here and on this similar thread, it looks like the computer runs about 2 mpg higher than the calculated mpg.

Giora suggested above that increasing your tire pressure would improve the accuracy of the dashboard gauge. I think that theory supposes that the distance is calculated incorrectly due to a variation in tire size. I never thought about the distance calculation, but assumed it must be fairly reliable in all cars, since odometer readings are so important for valuing a car. Could variations in tire pressure really account for a 4% discrepancy in the odometer, which would in turn affect the mpg calculation by the same amount?

 

Year of vehicle: 2012
Date: 4/6/12
Miles driven: 471.8
Gallons Pumped: 9.15
Hand-Calculated MPG: 51.56
Displayed MPG: 54.4
Average Speed: (Didn't check) about 6% local, 94% highway
Tire Size / Wheel size: 15in
Tire Brand / Model: Original
Tire PSI (Front / Back): Original
Seasonal Conditions: Sunny, ~55-80 F
Commute Length: 148 miles round trip
Hypermiling Techniques: Tried DWL, P&G

 

2nd fillup tonight. 435.4 miles on 7.746 gallons. 56.2 actual, 58.6 indicated. Still 2.5-3 high, but a MUCH better tank for me.
Cruise range said I had another 30 miles, so this pump may have clicked quickly. It'll balance out.

 

Thanks for your post.

We have nearly 70,000 miles on our Prius and I am
still waiting for the mpg guage to balance out.

Consisitently off about 3-3.5 (overead) mpg from day one.

 

All of the official information I got is posted here:
http://priuschat.com/forums/toyota-hybrids/102578-yaris-hybrid-reviews-8.html#post1498353

If I get more technical information or it is published on the Toyota.de website I will make it available in that thread.
Yaris Hybrid and Prius v are already available on pre-order on launch date in June.
The Prius Plug-in is also on pre-order, with lanuch&delivery in September.

 

Fillup #1 not listed since it doesn't count - don't know how full the dealer filled it or how long it was driven when I bought it....

Fillup #2 = 54.3 displayed, 51.78 calc'd, display high by 2.5
Fillup #3 = 57.1 displayed, 51.34 calc'd, display high by 5.8
Fillup #4 = 55.3 displayed, 52.55 calc'd, display high by 2.8

I didn't quite get the usual top off in on #3, so that one is a little high due to my fault. But it looks like the display is running about 2.5 - 3 mpg higher than calculated.

 

Year of vehicle:2012
Date:14apr12
Miles driven:381.4
Gallons Pumped:7.175
Hand-Calculated MPG:53.156
Displayed MPG:55.9
Average Speed:
Tire Size / Wheel size:175/65, 6.5x15 alloy
Tire Brand / Model: Turanza EL400 02
Tire PSI (Front / Back): 38/35
Seasonal Conditions: (please include A/C usage and temp setting if applicable) a/c on maybe 50%, set to 73*
Commute Length: 13 miles one way
Hypermiling Techniques: paying attention to HSI gauge

Still learning to drive the car to maximize FE. 2nd fill up.

 

F8L

Standard tires,wheels, etc. on Prius c II.

First measured fill-up was a throw-away since I paid little attention to driving technique and did not know any specifics of the dealer's fill. Measured mpg 44.4.

Now, from top off to top off, second fill read 60.8 and calculated at 60.97. That is, 197.8 miles and 3.244 gallons. So my measured actually bested the display by a small fraction. Temperatures ranged from 70 to 80. Overcast with occasional light sprinkles. 80 % city.

Will be posting at fuelly.com soon.

 

Thanks for going top off to top off. This does away with
any differences in pump auto shutoff. Its nice to see
the computer mpg gauge is accurate. I recall that
Wayne Gerdes from cleanmpg.com did the same with
a Prius C about 2 months ago and I believe from
top off to top off the gauge was within 1% of true.

It looks like you confirmed that as well.

 

Well, I would like that on my Prius 2010 - when I am topping off, I get 7%, when I am not topping off (about 1L difference) I get 5%...way far from 1%...

 

Ok...second tank down...here are the stats...

Year of vehicle:2012
Date:4/19/12
Miles driven: 531.5
Gallons Pumped: 9.3
Hand-Calculated MPG: 57.1
Displayed MPG: 58.2
Average Speed: 21mph
Tire Size / Wheel size: 15"
Tire Brand / Model: Turanza EL400 02
Tire PSI (Front / Back): 42/40
Seasonal Conditions: No AC use...nice temps in Columbus, OH
Commute Length: 5 miles each way to work....some other longer trips also..
Hypermiling Techniques: Pulse and Glide
Other: None


-M

 

Why did they not put such a nice summary (I refer to the pic!) on the Prius Gen 3??? :Cry:

 

2012 Stock C3 with alloys and Turanza EL400

Total odometer miles: 1223
Miles this tank: 456.8
Temperatures: 50-80 (weird week in New England)
Displayed MPG: 52.1
Calculated MPG: 50.94


Did not top off on either fill. Next measurement reported will be top off to top off.

 

That is the most scientific method to use for comparison
of calculated and displayed mpg's.

Thanks for your post