You won’t believe how low the gas mileage will be

Gasoline prices have fallen $0.50 a gallon since November, giving consumers some respite during the holiday season.

Prices have been falling since early November, with Americans saving a total of $200 million a day since Dec. 6, said Patrick De Haan, head of petroleum analysis at GasBuddy, a Boston-based provider of retail fuel price information and data .