[marine_corps]

Here's my final numbers of my experiment:

I only put 2.5 gallons per each gas station visit.
1st fill up 103miles/2.5=41.2MPG
2nd fill up 105miles/2.5=42MPG
3rd fill up 101 miles/2.5=40.01MPG
41.2+42+40.01=123.21/3=41.07MPG
Since my speedo has a 3% positive variation i subtracted 3%.. 41.07-3%= 39.83MPG
So my true corrected MPG on 87 is 39.83 MPG

[Kreylyn]

So my true corrected MPG on 87 is 39.83 MPG

And that's completly normal. Anything better than that is really just "user controled".

Krey

[TRPUT]

As long as that 2.5 gallons filled it to the same level each time, you've got solid data. It should be close considering your distances are so similar, but I've never added the exact same volume of fuel - even after identical trips.