We stock a wide selection of diesel fuel tank caps designed for heavy duty applications—whether you need a locking cap for extra protection, a vented cap to maintain proper tank pressure, or a standard replacement that blends with your truck’s polished look.

Lock & Secure Your Diesel Fuel with Polished Tank Caps

Our products do more than just cover the tank’s fill point. They secure your fuel, help protect against theft, and keep contaminants out of your semi truck fuel tank. Add in a tight seal, and you’ll cut down on emissions and keep fuel from sloshing out on rough drives. It’s a worthwhile purchase, even if it’s just peace of mind. We also offer smaller replacement parts like synthetic O-rings. Don’t overlook these components—an O-ring is what creates that airtight seal around your fuel cap, and it makes a big difference in preventing leaks. Here’s what you’ll find when you shop through this collection of fuel tank caps: - Locking fuel caps to keep your tank secure on the road. - Vented and non-vented fuel tank caps for maintaining system pressure. - Lever lock flush cap assemblies for a clean, aerodynamic finish. - Durable, built-to-last finishes that match your truck’s exterior. Every product is built for real-world conditions—so when you add one to your cart, you’re investing in security, reliability, and a better drive. Use the filter sort options on this page to narrow down by style, material, or fit, and get the right fuel tank cap for your rig.