America sits on huge oil reserves but still pays high gas prices, which is bad news for drivers hoping domestic drilling alone will bring costs down.

• The U.S. uses more oil than it pumps, leaving a daily gap filled by imports.
• Not all the oil drilled here can be used here, so a chunk of it gets sold abroad.
• That mix of exporting and importing keeps American gas prices tied to world markets, not to how much sits underground.
• Big reserve numbers sound reassuring but say little about what drivers pay at the pump.

Outlook: Gas prices will keep tracking global oil markets unless refining and export rules change.