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

Yes, it is intentional. After 3 years Toyota knows
that there is an error in the MPG gauge. They
have done nothing to correct it.

Our prius has nearly 70,000 miles on it it was off 3.5 mpg (over reading) when new and still over calculating by 3.5 mpg on
average.

It is not self correcting it is intentionally hard wired......

 

I filled up last night. My dash stated I was averaging 54mpg and my own calculation came up with 52.5mpg. This was I think around 420 miles and 8.1 gallons.

 

And Toyota is not alone, my Honda Fit was always 1 to 2 mpg's off as well, shady bastards!

 

First fuel-up since purchase

460 miles
8.839 gallons
52.0mpg calculated

do not know how to make it show average for the tank, but most of the display times is 53 or so, very small difference between calculated and displayed. +/-1 or 2 mpg.

 

You reset one of your trip gauges at full up to show your average for that tank.


mobile phone ?

 

What tire pressure are you using (compared to the manual)?
Are you checking it frequently?
I bet people that using pressure considerably higher than recommended will see a smaller difference between actual and indicated MPG. After all I think the reported figure is a calculation of number of wheel rounds @ The theoretical radius of the tire. The higher the pressure the closer the actual radius to the theoretical one.
Just a thought.

 

First fill up since buying the car. Using trip A mileage- 230.9 miles... car indicated 53.1 mpg. (BTW, the gas gauge was reading one line above 1/2 tank) The car took 4.44G to fill, so calculated is 52.03 mpg.

 

Filled up again today, went 378.9 miles on 8.195 gallons for 46.2 mpg's. Car indicated 49.0 mpg's.

 

All 4 tires are inflated to 44 psi which is max
sidewall pressure, tires are Michelin Energy Saver
195x65x15.

 

I can finally add to this thread as I filled my C Three for the first time this morning. 423.6 miles on 8.242 gallons, 51.4mpg calculated. 53.8mpg displayed, so about 2.5mg off.

I very recently aired up my tires to 41ish psi, and it's already noticably better. I drive 21 miles to work and managed 59.7 before, but this morning was 61.3 :rockon:

 

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

Year of vehicle:2012
Date:4/2/12
Miles driven:489.2
Gallons Pumped: 8.937
Hand-Calculated MPG: 54.8
Displayed MPG: 55.6
Average Speed:Oops..did not look at that 50/50 Highway/City Split
Tire Size / Wheel size: 15"
Tire Brand / Model: Turanza EL400 02
Tire PSI (Front / Back): 44/42
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

 

Year of vehicle: 2012
Date: 4/2/12
Miles driven: 471
Gallons Pumped: 8.39
Hand-Calculated MPG: 56.14
Displayed MPG: 58.6
Average Speed: ?? about 80% commute, 20% highway
Tire Size / Wheel size: 15in
Tire Brand / Model: factory
Tire PSI (Front / Back): factory
Seasonal Conditions: Temp varied from low 30s F to upper 70s. Noticed big drop in mpg when using heat in the morning.
Commute Length: 30 mile round trip, avg ~25mph
Hypermiling Techniques:
Can't seem to use standard pulse and glide technique with prius c. It either goes to regeneration mode or the elctric motor kicks in. I do have good luck with electric only on flats and downhill for sustained period.

 

Thx F8L...do you have any good forum links for using a Scanguage II and Prius? I have a SGII from years back, I'm new to driving a Prius, and I'm a new owner of a 'c'.
Note, I've never used the SGII in a Prius...TIA.

 

412mi readout 51.1
Actual after fillup 49.1
fillup at different pump and different weather

 

Another fill up and I had a slight improvement from 42.7 to 43.7 mpg. The readout says I was at 44.9 mpg. 300 lb driver, passengers 50% of the time, heater on during the morning commute and the a/c on the rest of the time. 80% highway 20% local. Not driving too hard or too soft. Just right. I live in an area where it is cold in the a.m. and warm in the afternoon with frequent windy conditions.

 

3 fill ups so far.
The Most Recent readout was 56.2 actual calculation 54.4. All three fill ups have been the same. The actual mpg is 2 mpg less than the readout.

 

Year of vehicle: 2012
Date: 4-8-2012
Miles driven: 590
Gallons Pumped: 6.158
Hand-Calculated MPG: 95.8
Displayed MPG: 66 MPG
Average Speed: Estimated 35
Tire Size / Wheel size:
Tire Brand / Model:
Tire PSI (Front / Back):
Seasonal Conditions: (please include A/C usage and temp setting if applicable)
Commute Length: N/A
Hypermiling Techniques: Drive in ECO mode- gradual accelerations and braking

I do not use the car to work as I can walk to work in nice weather which is the case now in Fort Lauderdale. I have been driving purely for pleasure and some of my trips have up to 91 MPG.
My calculated MPG at fill up does not make sense and I need more fill ups to determine what my true MPG is. Today I filled up right after the warning light came on which per the manual means I should have 1.2 gallons left. So assuming I topped off to the max when I first filled up, I used about 8.3 gallons which averages out to 71 MPG. I am still impressed.

 

Thanks for your point. I need more fill ups to get a more accurate MPG reading which based upon my driving and the Prius's gas economy will take a few months. It has been a bit surreal to drive here in Fort Lauderdale and get this kind of mileage with a car.