calculated vs. computer MPG - Please post your results

Miles...Gallons....MID Mpg.....Calc Mpg...Difference
435....... 8.93.........50.0.........48.71.......3%
406....... 8.37.........51.1.........48.51.......5%
429....... 8.93.........50.6.........48.04.......5%
312....... 6.26.........52.5.........49.84.......5%

It's frustrating that the discrepancy increases with the displayed mpg (I was getting 3-4% difference when the readouts were in the low 40s). I still haven't broken the 50mpg barrier with this car!

 

306.0 miles / 6.544 gals / 49.9 mfd / calculated 46.76

323.5 miles / 6.040 gals / 55.9 mfd / calculated 53.55

alfon

 

I have had my 2110 Prius for 2 months and I'm hovering around 40mpg. I drive mostly short distances. Is this the computer or the car? Anyone know?

 

Are you hovering around 40 mpg for the entire 2 months? Or when you reset one of the trip meters and measure for a few days do you never get much over 40 mpg? Big difference.

You should be able to get 50 mpg on some trips. But when starting cold and driving 1-2 miles if you get 30-35 you are doing well. You should be able to start cold (for CA) and drive 6-7 miles at 35mph without a lot of braking, and get 50+ mpg.

3PriusMike

 

Hello to everybody on the forum. I have a question:
The prius sold in EU is rated at: extra urban 3.8/ urban 4.0/combined 4.0 (L/100km with 17" wheels) .. so how is the average calculated? it shuld be 3.9 right?
Exemple: Toyota IQ EU engine 1.0l 5MT: extra urban 3.9/ urban 4.9/combined 4.3 (L/100km) how?

European Urban cycle=4km; Extra-urban cycle=7km

So... (4km x 4.0l/100km + 7km x 3.8km)/11km=3.8727/100km... ??

For the IQ: (4x3.9 + 7x4.9)/11=4.536.. witch is close to 4.3 combined but not quite.

Any thoughts on this?

 

Last fueling today, reported 4.9L/100km, calculated 5.44L/100km, that is, about 9% more.
Previous ones were:
- 5,1L/100km vs 5,48L/100km (7%)
- 4,7L/100km vs 4,65L/100km (-1%)
- 4.9L/100km vs 5,2L/100km (5%)
- 4,9L/100km vs 5.03L/100km (3%)

That is, averaged, 4,6% more than it actually is. Considering that at the pump, on average, they cheat, saying that you bought more fuel than what actually gets into the tank (how much on average, I don't know - I would guess 1-2% more) - I would say that the predictions of the Prius are quite accurate. I don't think other cars report fuel consumption any better than this.

 

3200 miles now. Computer has generally been 55-56 on every tank of 500 gallons. Actual has been 2-3mpg less than the computer.

 

Got my Gen III in August, and since then, have put 2,200 miles on the vehicle. I have never gotten below 50 mpg - on the computer, or measured. My measured mpg is typically 3 mpg lower than what I read on the computer.

 

Until the car warms up in the first few miles, the mileage is typically lower than the EPA estimate of 50 mpg. But anything over a couple of miles, unless you are running the car in very cold weather, your mpg's should begin to climb. Another factor that will drive the mpg down is the grade of the road you are driving on. Finally, if you operate in the PWR mode, or are rapidly accelerating every chance you get, yes, your mileage will be less than 50 mpg.

But in my 2,200 miles of driving since buying the Prius, I have NEVER gotten less than 50 mpg. Prior to the gas stations putting in 'winter blend" gas into the pumps (lower mpg than in the Summer), I use to get in the high 50's, and more than a few times, into the low 60's mpg - per tank of gas.

 

after 7370 miles
Computer average = 46.76 mpg
Manual calculation = 44.83

Prius V

Gasoline costs: $0.059 / mile

 

After 3558 miles ... computer = 50.4 mpg / calculated =48.0 mpg

 

So far the computer has been about 1mpg lower than calculated.

 

After 6073 miles, calculated mpg equals 52.3, computer indicates 53.9.

 

First refill at 390.2 miles, FCD - 47.2mpg, calculated - 45.4mpg, filled up with 8.588 gallons of regular unleaded.

 

It is rumored "there are three rev’s of Prius-III OEM FCD’s"
CleanMPG Forums - View Single Post - 2010 Prius-III P&G, SHM and WS FE techniques rehashed, defined and refined

I would like to ask everyone to report (edit previous one) the MPG numbers as well as your Prius's manufactured month.
It is shown at the right upper corner of the label located at the driver side of pillar.
Attached sample was taken at Detroit event in January made in October 2008.

Thanks,
Ken@Japan

 

The terrain really matters!! We live in where the terrain is rolling and not flat. Our mpg's vary between 46 and 48.5, which is still fantastic. This week we are spending the holidays in Perdido Key, Florida which is FLAT. Last tank calculated out at 53.5mpg. The FCD read over 56mpg. NICE IMPROVEMENT!!