Sonata I45 (YF - 2011+) :: Miles To Empty Reading Not Consistent After Filling Tank

This just gets stranger by the month. I could have sworn when I first got this 2011 Sonata that the console read 341 after filling it up for the first time. I thought it had said that after I filled it the second time (just after Hurricane Sandy - yes, before the long lines - I was lucky) and it read 329. On those occasions the console had read approx 67 & 69 miles to empty. I know I filled it with 87 the second time around. The first time may have been with 89. And when it stopped at 14.x I thought to myself, hmm, didn't it fill to 15.x the first time? Weird. So I went on with my life.

This past weekend it read 50 miles to empty and so I filled it again with 87 (same gas station I should point out). And just like the last time, before this time, it filled with 14.1xx and read 288 miles to empty. It just seems to me that "Miles to Empty" has slowly gone down. On the third filling I believe it may have read 303 to empty.

Is it me? I am imagining things here. Could have that much sludge/dirt/whatever it my tank because of the gas station I visited or the 87 and not 89 that I have been putting in? Oil and filter were changed in mid October and then again in mid March. Thats about to happen again on the 28th but also to have the required NYS Inspection done. What should I say to them if anything? Could I have picked that crappy of a local area gas station?