I averaged (says my gauges) about 33.5, I quickly did my math and found out it was off by 3 mpg, why is this

 

my scangauge sems to agree with my fit...pretty much within the mile.

 

I just installed a ScanGauge II, and will work on calibrating it tomorrow.

ERyan1189,
Many users have reported that the meter reads about 10% higher than actual results.

 

Is there a reason why our advanced computers can't do ( miles traveled / gallons used ) ?????

 

There is no reason for such large error. The meter is off consistently by 10%. The ECU has to inject precisely the amount of fuel into each cylinder. So the culprit is either the odometer (I don't think they would wanted another lawsuit again) or Honda simply added 10% to the total.

Scangauge uses the same data from the ECU. But allows user to adjust error correction.

I'm getting my Fit tomorrow and I'll play with Scangauge the next fews days for comparison.

 

I think it is a choice by Honda to embellish the results, and more than one magazine tester has been fooled by the display.

It is technically very feasible to produce accurate results.

The MPG display on my prior car, a 1999 BMW 328i convertible, was consistently within 1% error. After a few tankfuls (or is it tanksfull) I didn't bother to calculate it manually, since the meter was so accurate.

I have found the Honda MPG meter to be quite consistent, which is to say mine is always 10 or 11 percent high. Knock 10% off the displayed MPG, and there's my true result.

I don't understand Honda's choice in doing this.

 

Yes .. Honda locked out the trip computer! It seems they were not happy with the accuracy.. (They must of been telling the truth )

They'd rather have the BSM lie to you to a factor 12 % or more...

My last tank was 40.3 hand calculated... 45.4 on the BSM 13% or 5.1 mpg off.

I don't get it... why would honda embellish the reading so much? Do they think we can't do the math? GEES!

 

I find that the gauge on my car is within 1%-2% of hand calculations. But then again how accurate are my fill ups and consistency of fuel - since it can vary by gas pump, amount of over fill, temperature of the gas (both at fill up and during its life in the car), plus the amount and what kind of additives (ethanol etc.) The trip odometer looks accurate according to the GPS and speed is near right on according to my friends radar gun.

 

I have also noticed this discrepancy, in fact I was just talking about it to my brother today before seeing this thread. I always use the same gas and the daytime temperature here has not deviated significantly for weeks. I've had my fit for 2 months and it's always optimistic in its gas mileage calculations.

 

Took my first long drive today. The BSM was about 4mpg more than my Scangauge.

The speedo is pretty accurate compared to my GPS.

 

I know by now pretty much everyone on here knows about the BSM.

so my question is does anyone here work for honda? someone that can tell us if it is even fixable. can we take our cars to the dealer and have them fix it or are we just stuck with this BSM forever?

i recently called my dealer and they told me it is a AVG and can be off some. thats it. sounds like bull to me. but i'd like to hear it from someone who works for honda first.
Anyone?

 

I mostly drive in city, and every other day i drive a short distance on the highway to school, So far Ive had my fit for 4 weeks and Ive averaged 28-36 mpg, is that average? I see people listing close to 40!

 

I got about 8 k on my 09 fit now... lifetime mpg (Real deal) 36.4 mpg.

hit 40 + on 2 occaisions before the cold weather hit.

THE BSM is a consistent 12% or 4-5 mpg on the "generous side"

Has ANYONE found a fix for this yet?

Speedo... is dead accurate against my gps. So its just the BSM

 

I have close to 8,000 mi on my 09 as well. Maybe it's my imagination but I think I can sense an significant improvement in mileage compared to when new.

Last week, after a few months without checking mileage I reset my tripodometer and filled up the tank. After a few miles on the freeway doing 70 mph, the gauge was reading 50.6. After using the entire tank, 50% hwy, 50% L.A. commuting my gauge was reading 41.7, but manually calculated I got 38.6. That's pretty impressive and made me happy

 

I hope this is true for everyone. I'm only at 3000 and am getting around 31-32mpg av. At the same time the sub freezing weather here doesn't help.

 

31-32 avg ain't bad my friend, esp. with the cold temps. When new I was recording my mileage with every tank, driving basically the same routes during the week and would average 34-35 mpg manually calculated. I think it helps me that here in L.A. I'm not using the A/C too much as I did when the car was new.

 

I am not sure how my consumtion is because I am far lower than what everyone is describing, I am getting a consistant 31.5 on the clock and I range between 31.4 and 31.8. I do not do alot of hwy driving, but do these numbers appear to be normal? I see other posting 36 mpg and I wonder how that is being acheived?

 

Yes, I found these cars love the highway, once they hit sidestreets the MPG falls off fast. My wife drove my car for a month while hers was being repaired. (I had a coronary!)

Anyways, she was mostly side streets. Leadfoot Lucy managed to eek out a whooping 28 mpg out of my car. I average 36+ !

 

Believe it or not, hwy isn't the best for this car for mpg. Doing 65 to 70 expect mileage to be around 45-ish. When you're on the country roads where it's flat with not much traffic and you cruise along 40-50 mph, those types of roads, you'll see the instant mpg gauge hover around 70 mpg.

 

Higher mileage is possible at the highest gear and lowest rpm. And as speed goes up, wind resistance goes up exponentially. So it makes sense most cars get their ideal mileage around 55 mph (the speed limit during the 70's oil crisis).

As for our Fit's computers, I've noticed that it gets more optimistic when I ease off the gas and coast more. Seems that whenever I'm above 30mph and let go of gas, the meter goes up to 80mpg, which is not really possible because my speed is decreasing as I'm coasting. My computer says around 38mpg, by hand it's usually 34mpg in cold MN winter (with the diluted ethanol gas). My prev cars usually go up 3-4mpg when weather warms up.

Anyway I think Honda intentionally made the computer higher since MOST people do not calculate their mileage and just go by the computer, and it's a good marketing approach. People can brag about their high mileage to their friends. But of course nobody stops to ask, was that calculated by hand or the optimistic computer. Same psychology game with the gas meter in most cars. Auto makers are deceptive, and when there are no law regulations, they do whatever they want. Most safety standards such as seat belts, air bags, even lights came about from regulation standards, not voluntary by automakers.