20.5mpg? Something's not right here...

[D-Day]

I know something's not right here, and it annoys me. I filled up on the 29th, and topped off the night of the 30th. I added all my errands I did those days and I can only account for, roughly, 211 miles.

I wrote down I filled up on the 29th at 54,661. Filled up the night of the 30th at 54,986. That's 325 miles. I had to have messed up a number when I wrote something down - that or my odometer is running fast somehow. However, I've done a lot of short runs since then, as well as one today, and it comes up to 54,990. So it seems fairly accurate. I just don't remember where I racked up those other miles.

I filled up my tank the night of the 30th as mentioned, and got 15.8 gallons at $3.93/gallon; total $62.39 The price paid per gallon and how much I bought does add up to 15.8. That's not inaccurate.

Right now I'm going nuts wanting to know if I actually got it. I have attained 16mpg on the highway at 75-80mph+; is it possible that driving at 55mph for long periods of time (most of what was done with my trips in those roughly 30 hours) gave me 4 more mpg? I don't believe it. I can't. I know it's not entirely out of the realm, but not being able to account for those miles, I'm gonna have to chock it up to error and assume I just got around 14-15mpg.

Sucks. Guess I'll never know.