Can falling oil and gasoline prices be bad news? They can be for refiners�and that could come back to bite American drivers just as gas prices are coming back to earth.

Sticker shock (AP) Oil prices have fallen so far, so fast that turning crude oil into gasoline is now a money-losing business. A barrel of refined gasoline is worth $2.84 less than a barrel of oil, Reuters reports; earlier this year, gasoline fetched a hefty premium of more than $30 a barrel.

Gasoline...