I, too, have been screwed by the ethanol ripoff in MA.
I used to travel to Albany occassionally, and when filling up with NY gasoline vs MA gasoline, I suddenly got 2-3 more MPG! I managed to 'get by' on gas in CT as they didn't have ethanol, either...until a couple of years ago. Even with the 15-20 cent higher price in CT (highest gas tax in the country if I recall), the extra MPG more than offset the extra dollars.
But one thing this discussion has missed...that of seasonal adjustment. As of NOV 1, give or take, all gas in the colder regions of the country have had additives to lower the flash-point to improve cold weather starting. Also, some level of gas de-icer is also added to prevent freeze-up (I haven't poured a can of gas line de-icer in my tank in over 30 years!). Both of these additives knock about 1.5 mpg off my normally 19+ mpg minivan. Nowadays, the high 17s is all I get for mileage. Come spring, lower 19s. Just like clockwork.
And for those old enough to recall the Shell gasoline advertisements with Platformate (and later on, TCP...Tri-chloro-platformate)....--ALL-- gas contains platformate...it's a byproduct of the "platformer" that separates oil into its components such as gas, fuel oil, diesel, kerosene, etc... So much for advertising... By the way...my father spent his entire career in the gasoline business, so he was the "horses' mouth", so to speak.