Accuracy of Lifetime MPG

[hybridbear]

How accurate have you found your Lifetime Summary MPG to be in comparison with fuelly? Mine so far has been very accurate. Fuelly calculates 41.8 and my Lifetime Summary says 41.8 as of today. Have others found the same thing?

[jeff_h]

Thus far after 7,100 miles - Fuelly says 44.9, Lifetime Summary (which I have never reset) says 46.3.

 

 

 

Added - the display numbers being 1.4 MPG on the optimistic side are a bit more so than my 2010 FFH was (think the display was about 1 MPG optimistic), however is about the same as the 2005 Prius, where the display was about 1.5 optimistic over the actual miles/gallons dispensed.

Edited March 29, 2013 by jeff_h

[Da0ne]

i have 3200 miles so far my lifetime says 37.4 and fuelly says 37.1 but i havent reset the lifetime yet im going to wait till i get to 5k

 

just realized i can add missing fill up on fuelly

Edited March 29, 2013 by Da0ne

[lmp180psu]

I have found that with the inconsistencies between fillups due to the gas tank/fuel filler tube, i haven't been able to get an accurate picture of my mpg. I can't always fillup at the same station or tank, so that doesn't help. I have been letting the auto shutoff do its thing on the slower fill notch then topping off with 2 clicks method lately. One station it was within .1 gallons of computer, the next station was 1.1 gallons over. I have almost gave up trying to compare. I have just over 5000 miles. Lifetime avg per car is 39.7.

[ace8726872]

Thus far after 7,100 miles - Fuelly says 44.9, Lifetime Summary (which I have never reset) says 46.3.

That is a very impressive numbers Jeff_h!

 

I have 1900 miles on the odometer. Fuelly says 43.4 and Lifetime says 44.4. I am wondering if I should just put in 10 gallons at every fill-up so that I can eliminate the inconsistencies. What do you guys think?

[acdii]

Lifetime on mine is 36.1, and has never been accurate. The 2010 is much closer, but still not spot on, and that is only because two different people fill it up.

[tombarker13ffh]

My car shows 40.9 Lifetime MPG and my Fuelly shows 40.3. I'm sure the difference has to do with the dealer fill-up somehow..

[DeeCee]

Cars computer lifetime says 44.2 (was reset at 50 miles, now 5,270. Not on Fuelly but keep all my data on a spreadsheet at home. Actual computed mpg is 43.0.

[hybridbear]

Lifetime on mine is 36.1, and has never been accurate. The 2010 is much closer, but still not spot on, and that is only because two different people fill it up.

How does that affect long run MPGs? Having 2 ppl fill the car does not affect the gas you burned or how the car calculates how much you've burned

 

My car shows 40.9 Lifetime MPG and my Fuelly shows 40.3. I'm sure the difference has to do with the dealer fill-up somehow..

If the car wasn't full at dealer or if they reset the Lifetime when they received the car that could have an impact. Over time the impact will be minimalized due to an increase in data points as you accumulate more miles and fill ups

 

Thus far after 7,100 miles - Fuelly says 44.9, Lifetime Summary (which I have never reset) says 46.3.

 

Added - the display numbers being 1.4 MPG on the optimistic side are a bit more so than my 2010 FFH was (think the display was about 1 MPG optimistic), however is about the same as the 2005 Prius, where the display was about 1.5 optimistic over the actual miles/gallons dispensed.

That's quite the discrepancy considering mine is off by .1 MPG only

 

I have found that with the inconsistencies between fillups due to the gas tank/fuel filler tube, i haven't been able to get an accurate picture of my mpg. I can't always fillup at the same station or tank, so that doesn't help. I have been letting the auto shutoff do its thing on the slower fill notch then topping off with 2 clicks method lately. One station it was within .1 gallons of computer, the next station was 1.1 gallons over. I have almost gave up trying to compare. I have just over 5000 miles. Lifetime avg per car is 39.7.

This is very true. That's why a more accurate picture is determined by Fuelly and the Lifetime average in your car

[hybridbear]

I filled up today and the car calculated 42.5 and Fuelly, based on the gallons put in, says 42.6. That's very close. The car Lifetime MPG says 41.8 still but Fuelly says 41.9. It appears that at this point my car tells me less MPG than I'm really getting.

[acdii]

How does that affect long run MPGs? Having 2 ppl fill the car does not affect the gas you burned or how the car calculates how much you've burned

I stop at the first click, she tops it off, so tank to tank varies. It takes a couple tanks to equalize then. The 10 is much closer to the lifetime average than the 13 is. Over 2 MPG in the 13, but less than .5 in the 10.

[hermans]

I did the once a month fuel fill up this AM. The yellow warning light had been on for about 10 miles. I was able to get 12.5 gallons in the tank. Four clicks this time - the weather was about 58. On a 25 mile trip I got 52.8 and 48.6 on the return. Love the gas mileage - love the car. Got two comments on the car today. In the sun today the Bordeaux Reserve looked purplish.

Edited March 30, 2013 by hermans