There is a "filling" error based on the precise point you refill the tank. Which is highly variable. If you keep a spreadsheet of all your fill-ups and average them for a few thousand miles you'll see that the long term difference between calculated and the MPG gauge is between 1-2%. Pretty darn close.
The pre 06 Civic hybrid is reliably reported to be 5%+ "optimistic" (the gauge reads higher than actual).
And of course if you change the tires any difference in circumference (revolutions per mile) will further skew the MPG gauge. And the calculated MPG too since the odometer will also be effected.
I find on average the computer is pretty darn close. I uses a precise formula. (Known flow rate of injectors x time open x RPM=full consumed per cylinder per Revolution x minutes/miles traveled)... or something like that :? the
Had my first fill up in Wilkes-Barre the other day.
Put in 09.407 gallons; got an ugly look from a woman fueling up her SUV gashog. That big stupid grin on my face may have had something to do with that
The total mileage yesterday indicated was 487.
The gas tank is supposed to hold 10 gallons.
Assuming the dealer put 9.50 gallons in when I bought it (half gallon from Honda on delivery to dealer), as I figure it, I'm getting a bit more than 50 MPG.
The LMPG is indicating 47.0 at the moment.
Still learnig how to drive the "Silver Bullet" but I know the "short hops" aren't doing me any favors. Like the old Mercedes 220D I used to have, these Insights are at their best when out on the open road, in the right lane, zipping along at fifty or sixty MPH.
Hope this helps
I just had my first fill up after 509 miles.
I put in 8.42 gallons and stopped on the first click of the pump.