What do you think? Not much if any. If you are lucky there will be a gallon or so left but don't count on it.
The only way to know for sure is to run it out of gas.
How lucky do you feel?
Looking for a Used Grand Marquis in your area?
CarGurus has 1,718 nationwide Grand Marquis listings starting at $1,700.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts