MPG Meter Accuracy?
#1
MPG Meter Accuracy?
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...
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...
#2
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...
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...
#4
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.
#5
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.
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.
#9
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.
I had it done and now mine is within 1 mpg of my calculated mileage.
#11
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.
#13
EDIT:
Found link about TSB.
https://www.fitfreak.net/forums/2nd-...g-display.html
Last edited by silentnoise713; 08-11-2012 at 11:05 PM.
#14
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.
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.
Last edited by Dwalbert320; 08-11-2012 at 11:20 PM.
#17
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
-Dustin
#18
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.
#19
Last edited by silentnoise713; 08-30-2012 at 01:38 PM.
#20
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.
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.