Another thing to watch out for when traveling out-of-state are sneaky tricks at the local gas stations! Beyond the obvious, such as how many of us New Jersians sometimes sit like dunderheads in our cars, waiting for an attendant to come out (note to self: most states require you to self-serve and pump your own gas), different states may have different gas filling protocol. Some might let you pay at the pump, some require you to prepay. And then some try to pull a fast one on you to make you buy more expensive gas:
I am referencing this post from "Money, Matter and More Musings" because he has the cold, hard pictoral evidence of gas stations switching up the usual "left to right" order of increasing octane grades typically seen at the pumps. The worst I've seen (and nearly used!!!) was once, the diesel line was the leftmost pump, and it was not only the same color as the rest (usually diesel is green or bright red) but even the sign saying "diesel only" was the same b/w lettering as the other signs. Urgh.
As of now, I believe you still have to physically punch the big "87" or "89" or "91" signs/buttons to get the gas flowing, which should automatically alert you to any potential errors. But if the mixup of ordering L-to-R is part of some ultimate "Fooled ya!" plot, then pretty soon they will do away with the extra push-button step (and thus many impatient people will happily pump away, pleased they are saving some precious seconds of their time, but NOT realizing they are, indeed, pumping away some extra $$$$).