I chose Mobil since it is the only on your list here in Maine. I usually buy either Exxon (which bought Mobil so I figure it's the same thing) or Irving.
I don't see much difference in the way the Zetec performs based on brand, but Irving regular claims to have a detergent the others don't. I know a steady diet of anything else and I feel a need to add injector cleaner more often.
But it seem more important as to the station itself. Some have reputations for water, etc.
Find a place that treats you right, controls the price the best, and that your car likes.
