He put the gas cap back on as the car voice belched.

It is an oil field with a gas cap in the Paleocene structure.

"Somebody's got to take off the gas cap," he pointed out.

Guy pulls off the gas cap, closes one eye and looks inside, like he can actually see something.

Buyers with deft fingers can even open the gas cap.

Since a gas cap is not normally a part of a car's definition, it would be given no weight.

He went around to the back and unscrewed the gas cap.

Turned out he had a rag for a gas cap.

The field is composed of a natural gas cap, oil column.

This gas cap pushes down on the liquid helping to maintain pressure.