Hi Gerald, maybe next time in Atlanta or wherever, look for a dollar or 99 cent type store, maybe also Walgreen's. MY aspirin is Family Value brand, got 150 ct. for 99 cents 325 mg. I still can't think of any other reason for MPG difference on the Atlanta run besides the gas itself. I wish Everclear wasnt so expensive!
Since your Chevy is OBD2 it is possible to use a Scanguage or a decent scantool to actually see the O2 sensor voltages and the LT ST fuel trims in real time. Being able to see this info to me is one of the best things of OBD2 systems. You can get a far better idea of what's going on this way. Particularly you can see the FT #'s this will show if the ECU is adding or sbtracting fuel compared to the middle of range setpoint, the number zero. Without this info you almost might as well be working w/ a distributor/carb. setup. You have set the stage for improvements already, a scantool/scanguage will let you "see the stage".
About your old ship, USS Johnston DD821 was a Gearing-class destroyer WW2 built. She was FRAM-1 modernized in early 60's. the ASROC box launcher was mounted midships between the stacks, the gun mount immediately forward of the bridge was removed and provisions for the helo deck were made aft. The unmanned remote control DASH helo's were an experiment of that era to add longer range ASW capabilities to fleet escort ships out beyond ASROC range, but ultimitely were discarded due to control issues like you witnessed! ASROC could launch Anti Submarine Rocket Torpedoes, with atomic warheads to increase kill probability. I found a website for your old ship, very smart lethal lookin Tin Can! There is a pic of her alongside USS Enterprise, and from your visit to Saudi Arabia I would guess you were in the Med, 6th Fleet?
BTW Gerald I hope I caused no offence in my little vignette good 'ol boy story I made up above about gasoline superstitions! After I came up w/ that, I realized where you live

I've been to Georgia once many years ago, I thought it was beautiful, the people super nice, wish I could have stayed much longer. I would just love to hear and talk to some of those old-time good Old boys from your region, I'd probably start to pick up an accent after a few days!
I just added a fresh dose of MPG Remedy to the Subie's tank- 6 uncoated aspirin crushed added to 5 oz of Everclear and 2.5 oz HEET yellow bottle gas dryer. After letting sit a day w/agitation several times, added 1 oz of hydrogen peroxide then added to tank w/ 4 oz of Lucas fuel treatment, filled tank w mid grade no-brand gas. I noticed the aspirin would go up in suspension when I swirled the jar, then would settle out to a thin layer of white residue on bottom. Don't know if or how much of the aspirin went into solution, but some never did. Maybe the white residue is binders or other? Going to just drive as normal, see how it does then compute #'s at the next fillup.
But I won't buy gas at Gus Filbert's fillin' station!
Tracy G