• Pressure relief prevents fuel vapors from exiting the fuel system under normal operating conditions. This allows an escape path for pressure in the event of an impact situation where the fuel tank has collapsed. It also permits pressure to escape if the vapor management system malfunctions.
• OE Vacuum relief prevents fuel vapors from exiting the fuel system via the fill tube under normal operations. This allows an alternative path for air to flow into the tank if there is an obstruction in the vapor recovery or vapor management systems. It also permits the fuel system to normalize air pressure during natural vacuum situations.
• A "Lost Motion" feature permits the cap handle some freedom to turn while maintaining a seal, which could aid in the prevention of fuel tank leakage during a crash or impact.
• A "Breakaway Groove" allows the cap to remain sealed and prevent fuel leakage during a crash or impact, even if some of the cap has broken away.
• A "Torque Override" feature aids in the proper installation of the fuel cap. It produces an audible click as the o-ring that seals the cap is properly compressed.

Caps with controlled pressure release technology allow pressure built up in the fuel tank on hot days to be released gradually when the cap is opened. This prevents fuel from erupting and spraying out on the motorist. Below are the three types of controlled pressure release cap styles (not all styles are available for all applications):

Push Vent
Push button to
release pressure

Key Vent
Push key into lock to
release pressure

Twist Vent
Push & 1/4 turn to
release pressure

The color of the cap can be used to identify the vehicle's fuel compatibility. The physical cap is the same, regardless of color.

Gasoline
Black is the standard
Fuel Tank Cap color for
vehicles that take Gasoline

Flex (E85) Fuel
Yellow indicates your
vehicle is Flex (E85)
Fuel compatible

Diesel Fuel
Green serves as a reminder
that your vehicle only
takes Diesel Fuel