I'm just getting settled into my new Fit (2011 AT Sport) and still on my first tank of gas.

I see two MPG gauges -- one is what I assume is the instantaneous reading, this one hovers tantalizingly between 40 and 80 MPG. The other is the Average readout which is currently showing a more down to Earth 31.8.

How accurate is the average reading? I assume it is some sort of moving average with oldest data eventually discarded, or is it a lifetime reading? Does it reset after so many miles, hours, revolutions, gallons, or when I fill up?

Just curious...

 

It resets when you rest the tripmeter. I've found it to be pretty accurate over all, generally within a mile or two of the right millage. Probably within the error of the odometer at least.

 

+/- one or two for me as well.

 

I've been tracking this for over a year, and the mileage meter is pretty accurate, even more so, now that I'm able to use a GPS to keep track of miles covered. In my experience, less than +0.5 mpg error, averaged over about 18,000 miles of records. You may see much wider tank to tank discrepancies between what is reported and what you calculate from individual fill ups, but this is because it is so difficult to establish a consistent fill on a Fit, due to the very long filler tube. Over time, it averages out.

 

My gauge has been pretty accurate as one can see by the recent data:

8/3/11 32.0 Shell 87 AVG MPG Gauge = 32.8
7/27/11 30.8 Shell 87 AVG MPG Gauge = 31.0
7/21/11 33.9 Shell 87 AVG MPG Gauge = 34.5
7/14/11 30.2 Shell 87 AVG MPG Gauge = 30.6
7/11/11 36.1 Shell 87 AVG MPG Gauge = 35.2
7/1/11 38.3 QT 87 AVG MPG Gauge = 40.2
6/24/11 30.8 Texaco 87 AVG MPG Gauge = 30.9
6/17/11 32.4 QT 87 AVG MPG Gauge = 32.4
6/10/11 31.6 QT 87 AVG MPG Gauge = 34.0
6/7/11 34.5 Shell 87 AVG MPG Gauge = 34.5

Over 10 fill-ups my actual AVG MPG was:33.06 and my gauge averaged 33.61 so on the average it was 1.66% optimistic. I would say that is pretty accurate.

 

Mine is either spot on or about 1.5 mpg off on the high side, no higher though

 

So, I think my car has a very nice gas mileage after all......I can see a number of 40 MPG pretty often on that guage......

 

2009 MT Sport. Mine is 15-20% off on the mileage (showing more than the real ones).

 

The 2009's had an error in the ECU that caused the mileage to be reported about 10-15% high. There's a technical service bulletin, 09-086, to reflash the ECU to fix it.

I had it done and now mine is within 1 mpg of my calculated mileage.

 

Any word for the 2012's? My 2012 Fit Sport just turned 1 week old today. It's almost time for my 1st fueling; it came off the lot with a full tank of gas.

My gauge says 27.3 mpg average.

 

Sounds about right. My first tank avg. was 26 mpg. Partly due to engine break in and should continue to improve with subsequent fill ups. reset it with the next fill up though.

 

My 2010 usually shows from 1 to 2 mpg's above actual so about 3 to 6% off. I think all cars have this problem.

 

Hi, new '09 owner here. Can you point me to this TSB? Mine reads more than 10-15% high. Two tanks back it showed 42.x MPG but paper calc was 34.x. It is always way too optimistic. Thanks in advance.

EDIT:
Found link about TSB.
https://www.fitfreak.net/forums/2nd-...g-display.html

 

There is such a big difference between highway and city....No wonder you guys get different readings...

On the Highway I get 38 mpg exactly. In the City I get no better than 26 mpg.

There is such a big difference between the two. How can anybody's average be compared with any accuracy?

If a person gets 80% highway he will get closer to 38 mpg.

If a person gets 20% highway he will get closer to 26 mpg.

With every mile in the city and mashing on the gas at every light I've had her down at 22mpg.

Driving 55 mph I might get her up to 40mpg...But I drive 70 mph with a steady 38 mpg.

Average is right around 31 mpg right on spec. No way you are getting 31+ in the city...unless you drive like a granny...and with cold weather + wind at your back...and being towed by a Honda Pilot.

 

My Stats after three years. None of this one tank BS.

Mileage is 37,000 kms or 23,000 miles.

Results were 38 mpg Cdn or 31.6 US gal or 7.4 L/100 km

 

So far, my MPG readout is "optimistic" to the tune of 1.5%. This is not a large discrepancy. It's never been off by more than 5%. The "optimism" is, however, pretty constant.

 

I'm a bit of a nerd, so I've been tracking mine and comparing the readout with hand calculated for every tank on my 2012 Fit Sport Auto. The average MPG meter seems very accurate, but almost exactly 1 MPG high every time. So, if I just subtract 1 MPG from what it says it's dead on what I calculate at the fill ups. Of course there's always a little variation, but I attribute that to the small tank and the extra long fill up hose that connects the tank to the fuel cap. I would imagine there's a little room for error there depending on how sensitive the gas pump shutoff is.

-Dustin

 

thanks for the tsb info, i got this done on my 09 when i was at the dealer getting maintenance done. they reset everything so will see how things go.

i think my '12's mpg meter is fairly accurate from wat i can see at this point. car's showing 28.8mpg, i pumped about 7.5gals (first fill) the other day and car has about 230+ on the odo. for a first fill, not bad as usually it's the worst mpg.

 

Quote:

Originally Posted by silentnoise713

Hi, new '09 owner here. Can you point me to this TSB? Mine reads more than 10-15% high. Two tanks back it showed 42.x MPG but paper calc was 34.x. It is always way too optimistic. Thanks in advance

Since getting the TSB fix (hurray for free warranty work!), my MPG calc now actually reads almost dead accurate. Post TSB, first tank was UNDER estimate by just under 1MPG and second tank is OVER by a little OVER 1 MPG. Good enough for me. I'm happy yet sad to no longer see AVG in the mid 40s . Back to reality of averagin mid to low 30s.

 

The first tank on my 2012 sport MT was 42 calculated. the display was said like 38
I was surprised it was so high I didn't really try, but I coast a lot when I can. I noticed on my old fit it was rarely as accurate when I was hitting 40's, and I hit 50 one day with a huge tail wind and it read 35 something. But I rechecked receipts, fuelly.com, and my road trip app and it was right.