Fuel Cap

The FUELAB Fuel Cell Filler Cap (MPN 63701) is a precision-engineered screw-on fuel cap designed for high-performance fuel cell systems and custom fuel tank installations. Built for automotive enthusiasts, fabricators, and professional mechanics who demand reliability in fuel system integrity, this aluminum fuel cap prevents fuel evaporation, contamination, and spillage while maintaining a secure, leak-free seal under demanding conditions. Whether you're building a custom race car, restoring a classic with a modern fuel cell, or upgrading an existing fuel system, this cap delivers the durability and functionality serious builds require.

Constructed from lightweight aluminum and finished in gold anodize, the fuel cap combines corrosion resistance with a clean aesthetic that complements custom fuel system installations. The screw-on design provides a positive mechanical connection, eliminating the risk of accidental detachment during vehicle operation or track use. At 2.48 inches outer diameter, the cap threads securely onto compatible fuel cell filler necks, creating a vapor-tight seal that meets the demands of both street and competition applications. The compact profile—measuring 4.5 x 2.35 x 4.85 inches overall—fits neatly within engine bay packaging constraints without requiring additional clearance modifications.

This fuel cap is ideal for custom fuel cell installations, fuel system upgrades, and high-performance builds where OEM filler caps are incompatible or insufficient. Mechanics and fabricators value FUELAB components for their engineering precision and material quality; this cap maintains that reputation while offering straightforward installation on any fuel cell with matching filler neck dimensions. Weighing just 0.34 pounds, it adds negligible mass while providing essential fuel system security during acceleration, braking, and cornering forces encountered in performance driving or motorsport competition.