I'm new to this forum and searched around for a thread on this topic, but couldn't really find one. I bought a used 2009 Fit Sport with about 40,000 miles on it. I've filled the tank 8-10 times since I've had it. Each time I calculated the MPG by dividing the miles since the last fill-up by the gallons put in. Each time, my MPG calculated via that method is significantly lower than what the on-board MPG gauge reads. (yes I reset the tripometer each time). This morning I filled up and calculated my MPG to be 31.23, while the onboard guage read 35.6 (over 4 MPG higher). Has anyone else expereinced this? Is there a way to fix the gauge (assuming it's not giving me an accurate reading)?

Thanks in advance for any help/advice.

 

https://www.fitfreak.net/forums/2nd-...indicator.html

Summary: There is a reflash the dealer can perform it it wasn't already performed regarding inaccurate mpg gauges.

But as a side note, the tank is so small that if you even put in, say 0.5 gallons more than you usually do for a given mileage, it will throw your calculated mpgs off ~3mpg...

 

Same as above
1) Check to get the software update from the dealer
2) Make sure your tires are correct size/inflated properly-check your speedometer with a gps device or to make sure it is accurate.
3) Keep a record over a few tanks of gas to account for different gaspump shutoffs.

 

The 09's had a problem with the mpg indicator. Indicated 10-15% higher that you actually got. There is a download available at the dealer, and a bulletin went out from Honda about it. ALL 09's. When mine was up-dated, it began indicating almost perfectly what it really got. My '10 is dead on accurate.

 

I'm guessing a new 2012 fit won't have that software glitch? I just filled up my tank for the second time since buying the car and I will be doing the same manual calculations over several fill ups to compare that average with what the computer says.

 

Had ten fillups on my 2012. Never varies more than 1.5 MPG either way. It's typically more a glitch in the gas pump (how much it fills before clicking stop), than it is the Honda's MPG computer.

 

MY 2012 is consistantly 1mpg optimistic.

 

This is a known issue with the 2009 car. The on board computer in my car was off by 15% on average. After the re flash at the dealer the computer is within 3% on average to actual mileage.

 

Thanks for the responses. I'm guessing that my '09 never got the software upgrade, so I'll have the dealer check that out.

 

I think it's interesting how much things still vary car-to-car even after the reflash. Before the reflash, mine was always 4-5 MPG optimistic, and now for the last year or so since the reflash was done, it's still almost always 1-3 MPG optimistic almost all the time. I think I've only had maybe 3 or 4 tanks ever where it was either right on my calculation or below it. Interesting that the reflash seems to make it better for some but no so much better for others (like me).

 

I just filled my 2012. 28 mpg on the computer and 27 mpg actual, filled at the same pump I filled at last time.
It really doesn't make much difference if the computer is off, It's easy enough to make the calculation when you fill up based on the trip odometer. In the end does it really matter if the computer is off by a few mpg? It seems that many of us are going to calculate our own mpg anyway.

 

Correct, and as I stated, if you top off your tank after the pump clicks or you stop when it clicks matters. The tank is so small that even half a gallon more will throw off your calculated mpg by up to 3.

 

I've filled my 2013 FIT Sport MT 18 times and recorded the fuel, distance and the estimated M/G. My over all calculated M/G for 18 tanks is 34.7 mpg. [Range 31.5 - 39.7] The 'estimated' mpg has averaged 1.3 mpg more than calculated. I've seen differences as much as 3.7 higher for estimated vs calculated. Only 4 times has the estimated been lower than the calculated - the greatest difference being -0.9. Over all, the estimated has averaged 1.3 mpg greater than the calculated. [Range 33.0 - 41.3] I've kept mpg log books in all my cars (and motorcycles) for the last 50 years - just like my dad before me.

 

The on board meter always gives me 1-2 too many mpgs. Close enough for me...

 

I've been tracking this for awhile. Although individual fill-ups produce +/- 4 mpg differences between the Dash Meter and the hand calculated mpg, over the long run, it all sort averages out.

 

will the dealer reflash the computer for free ? like it is an actual free update that Honda has to do to a car even if it's not in warranty?

 

you're talking about the fix to '09s MPG data tables? It's not a recall, just a TSB. They may goodwill it, otherwise they'll charge $$ for the electronics guy to reflash it. If you have an 09 make sure the Lost Motion Spring (LMS) recall was performed.

 

This explains what I've noticed since owning my Fit. My last vehicle, a Nissan Frontier, had a tank twice the size of the Fit's. I never saw a variation in my average fuel economy with the truck. My Fit, however, is impacted greater by different pump cutoffs.