Well, over one tank it would make a difference, but over many tanks it gets pretty accurate.

The 43.59mpg you got will be offsett by the next tank that you stop at the first click at.

 

when you topped off for this tank and made hand calculations of your mileage, did you use the number of gallons filled until the first click, or the number of gallons on the display after you topped off?

if you used the latter number, you would have calculated your mpg with 1.3 gallons more than you actually used for that tank, leading to a much lower hand-calculated mpg.

(mpg = miles driven / gallons used
if gallons used increases and distance driven remains the same, calculated mpg decreases)

 

On my last tank, I used 10.59 which is the amount of gas until the first click. I did this because that is what I have done in previous tanks. However, I believe I can be more consistent when I top off because I am not reliant on the pump auto-stopping the same way every time. Therefore, I will use the topped-off amount from now on.

 

right, now that you're using the topped off amount, it should be more accurate.

i've driven my car for almost 16,000 miles and the mpg meter has never been more than 1 mpg higher than my hand calculated mpg. perhaps that's because i haven't gotten over 51 mpg for a tank yet, while others who have 60-70 mpg tanks experience larger discrepancies.

 

Sometimes when that happens I'm tempted to just call that a tank, and fill up again so that I can have the satisfaction (albeit an empty satisfaction) of having an insanely high "tank".

 

Sure would look cool to have a little bubble plotted at 120 MPG on your GH database chart.

 

I am confused. today I was cruising on a level freeway (CA) at 60 mph and the Instant MPG read 100 mpg for an extended time. I classify this as a defect of the on board calculator. Other times at lower speeds it does the same thing. Has any body else had this problem? does Honda comment?

 

I think you achieved the much-sought-after EV mode. Did you see a few bars of assist too?

 

I may be way wrong here or just misunderstanding what is being said but...there is no possible way that we can know exactly the amount of gas that we used from one tank to another.

If we fill up to the first click on this tank and again on the next, aren't there still many variables...gas station, exact pump, temperature outside, ect?? I may be so wrong but with this thinking, I would expect that the computer in the car is more accurate.

Please let me know if I am in error here.

Jessica

 

Lets do the math.

Lets say that between different pumps there was a 1 gallon swing on what the top off level was (first click).

So lets say over ten tanks you were able to drive 500 miles with 10 gallons (so ten tanks at 50 mpg). And you had set the experiment up so that you KNEW this was the value (possibly you weighed the tank of gas on a scale).

Okay so you know know what the exact mpg is, and over those ten tanks of gas you fill up at ten different stations, and you find that based on the click off point you get half of thempg calcs below 50 mpg and the other half above.

No in real life, if the on-board computer was more accurate, you would expect that this would happen when you compared the computer to your hand calcs. But what really happens, is that the on-board computer is ALWAYS low by about 1 -2 mpgs. This means the computer is under estimating the mpgs, and therefore is less accurate.

Additionally, even if one hand calc (by taking the total miles and dividing by the gallons pumped) is off, an average over several tanks the value will be dead on accurate.