They do, sometime around fall/winter time they switch it up to "e70". I haven't figured out a way of telling when you get what. Luckily my car will compensate for the difference, I'm not sure what a carbureted car will do. But it's not a problem at all, even when I'm switching between 93 and e85, its ok to have some 93 still in there (the less the better obviously), the car will adjust for it.