Fuel tank size on a 1999 f-150?

The fuel tank size on a 1999 Ford F-150 varies depending on the configuration of the truck. It could be either a 26-gallon or a 36-gallon tank. To know for sure, you'll need to:

* Check your owner's manual: This is the most reliable source of information.

* Look at the fuel door: Sometimes the tank size is printed on a sticker on the fuel door.

* Check the sticker inside the driver's side doorjamb: This sticker lists various specifications of the vehicle, and may include the fuel tank capacity.

Without more information about your specific 1999 F-150 (cab style, engine size, etc.), it's impossible to give a definitive answer.