The difference in winter and summer gas is the vapor pressure, you can use less light ends in the summer time, We no longer use MTBE{methyltertiarybutalether}
at any Shell California Refineries, we are now making carb3 gasoline and yep it cost more, if a California refinery is down for maintainance or problems the price will go up, because you can't get it from anywhere else, you can't bring it in from outta state, if that makes you unhappy, kick a Democratic enviromentalist in the nuts!!!
