Hi Gerald and Nate, I surmised from reading the patent and Dan's input that it should be uncoated. But Nate if the coated works too for you then Woo-Hoo! Either way nothing wrong w/ having some Aspirin around it still works for it's Original intent...
Gerald I've noticed here there are stickers on pumps telling of the alcohol content. Instead of the retailer you might ask the State DMV or ask them who would know of the state or local reg's regarding gas formula's in Emissions counties/areas of Georgia. Since it's pretty much flat driving- the variables can be the Gas itself, and far less possibly that the truck is all warmed up when going back. If the Atlanta gas is Oxygenated, that's the variable I can think of, maybe there are other differences.
In years past on a trip to the Calif. Bay Area I filled up in the East bay and drove back to Reno and noticed a definite diff. in the avg. MPG with the Calif. gas. Back over 20 yrs ago a freind worked for an owner of several stations and did maintenance/ retrofit to the pumps/tanks of these stations. These were Chevron stations, in the course of all this my freind had some training and classes from the Chevron refinery people in the San francisco bay area where there are a group of oil refineries. He learned that at least back then Calif. had strict quality and formulation regs on gas for sale down there, where in Nevada it was less so. The Chevron people told him that gas that was either old or out of spec for the Calif regs- that was the gas that went in the pipeline to up here to the Sparks tank farm. Bottom line we got reject gas! Plus the retail market down there is huge, far bigger than northern Nevada, and the refineries are local to that region, where gas for Reno and region comes up in pipeline. Ergo- the Calif gas is fresher! Now this is anectodal info, but it's the only window into that industry I ever had.
There is prob. as much tales and superstition about gasoline as Halloween! "Clem, dontcha evver buy no gas from a fillin' station where they got's a Hupmobile out back! Nossir, Lemme tell ya'all 'bout what happtint to Goober and Stumpy when they had a run up 'round Bugtussle for a load o' Shine from 'ol Pappy Sutton's still...See now, Goober had ta use some o' Pappy's first run leftover wash as fuel fer ta git on back down 'fore sunup, 'an he was runnin them new Super Spark plugs in his flathead- 'an that flathead was jest a purrin' as nice as ya please , was what Goober said, but then he said that soon as he was coastin' thru the bend down thar in Hog Hollow he plumb a ran outta fuel, so him an' Stumpy had'ta sneak through a hole in the back fence over at Johnson's Creamery 'an siphon sone gas outta Old Man Johnson's milk truck. Now you know how old man Johnson was always gettin' gas fer that 'ol '47 Dodge from over yonder at Gus Filbert's fillin' station, 'member how he was always braggin' ta Aunt Sadie 'bout how he was gittin' that cheap flatland gas from 'ol Gus an' savin' a Whole Penny a gallon that 'a ways. But Goober, he says that him an' Stumpy got back to his Model A 'an put that flatland cheap gas they siphoned outta 'Ol Man Johnson's milk truck inta his tank, an' they cranked 'an cranked 'an cranked 'till the battery was plumb dead. That Flathead jest wouldn't plumb start, no matter what they did, 'am by now the sun was jest a 'comin up! 'An Goober says that's when Sheriff Crabtree came 'on by and smelled that Shine Goober had in them jars in the back, 'an heck Goober had jest got done doin' a stretch up in Haynes County! Nossir it don't look so good fer 'ol Goober! Now Everbody knows that that 'ol Hupmobile out back 'a Gus Filbert's fillin' station, why heck that 'ol crate hasn't gone no-where since before the War! So Nossiree No Ways no how am I ever' gonna git any more gas from Gus Filbert's or Enny other fillin' station where they's got's an 'ol Hupmobile sittin' round' bout the place, Nossir!!"
So there Freinds is another valuable tip on Gasoline Selection!
Gerald- besides the gas possibility, can you think of anything else that might cause the difference? A prevailing wind? Do you habitually haul a load one way? Reaching here. Was that Tin Can you sailed aboard WW2 construction like a Fletcher or Gearing class? Not pertinent here, just curious? And again- thanks for Serving Sir!
Tracy G