Factors affecting mileage include:
* Vehicle condition: A well-maintained engine and properly inflated tires will yield better results than a neglected one.
* Driving habits: Aggressive acceleration and excessive idling significantly reduce fuel economy.
* Load: A heavier load drastically decreases mpg.
* Terrain: Hills and mountains will lower your gas mileage.
Realistically, expect to be closer to the lower end of that range (or even lower) in city driving, and perhaps slightly higher on the highway if you maintain a steady speed. Don't be surprised if you regularly see fuel economy in the single digits in heavy city traffic or with a heavy load.
