Not sure what is different, if anything. I wonder if you guys up north don't run a winter blend all year around where the USA refineries do summer blends and switch to winter in october. Winter has more preservatives in it to insure it stays good during the cold months. Summer gas goes bad fast, winter gas lasts quite a bit longer. We also have a lot of ethanol in our gas. Standard gas can be up to 10% ethanol and not be marked with "contains ethanol". Most gas stations have 3 pumps, standard not marked usually 87 or 89 (10% ethanol), premium ethanol 91, and super premium ethanol 92 or 93. It is very tricky to find a gas station that has true ethanol free gas, most of the time it can only be found at a marina. A lot of stations get busted every year for marking gas ethanol free and then putting the 10% blend in it. (10% blend is a lot cheaper than ethanol free).
