DETROIT (AP) — Ford soon will offer a natural gas version of its F-150 pickup truck, the most popular vehicle in America.

The company is the first Detroit automaker with that option in a light-duty pickup truck. Ford, General Motors and Chrysler already have natural gas-powered heavy-duty trucks.

Ford says natural gas will be available on the 2014 F-150s with 3.7-Liter V-6 engines.

The trucks will have factory-installed valves, pistons and rings to handle natural gas and gasoline. The option will cost $315. But buyers will have to pay a factory-approved installer to put in new fuel tanks, lines and injectors. That will cost $7,500 to $9,500.

Ford says natural gas costs the equivalent of $2.11 per gallon. The average regular gasoline price in the U.S. was $3.62 per gallon on Tuesday.