Diesel Fuel Cap Cover for Commercial Trucks
40–68 Gallons of Diesel • Zero Protection From the Factory
Diesel is expensive. Diesel trucks carry a lot of it. And the fuel cap on every chassis cab is completely exposed. The Work Truck Fuel Vault is the diesel fuel cap cover that fleet managers and contractors trust.
Founders Edition pricing — starting at $139.95 (Save up to $60)
Diesel Makes Your Truck a Target
At $4–$5 per gallon, a full diesel tank is worth $200–$350. That's a big payday for a thief who only needs 60 seconds and a siphon hose.
- Diesel chassis cabs carry 40–68 gallons of high-value fuel
- The fuel cap is completely exposed — no door, no cover, no lock
- Diesel theft costs $500–$1,000+ per incident including downtime
- Fuel contamination (sugar, water, DEF mix-ups) destroys diesel engines
- Locking caps provide minimal security against diesel siphoning
- Fleet diesel shrinkage costs thousands per year across multiple trucks
The Diesel Fuel Cap Cover That Works
The Work Truck Fuel Vault is the armored diesel fuel cap cover purpose-built for commercial chassis cabs. Full coverage, real lock, real protection.
- Armored cover over the entire diesel fuel filler area
- Tumbler lock with security torx — tamper-resistant
- UV-stable composite withstands diesel, chemicals, and outdoor exposure
- Bolt-on in 8–15 minutes — no drilling or cutting
- Purpose-built for Ford and Ram diesel chassis cabs
- Made in the USA — Sarasota, Florida
The Part The Factory Forgot
The Work Truck Fuel Vault is an armored, locking fuel door that covers the entire fuel access area on your work truck. No more exposed caps. No more easy targets.
Why Didn't This Exist Before?
Despite billions lost to fuel theft every year, nobody built a real solution for commercial work trucks. Here's why.
"Good Enough" Thinking
The industry defaulted to cheap aftermarket locking gas caps. A $15 key-locked cap was considered good enough — until thieves proved otherwise with a pair of pliers.
Upfitters Focus on the Body, Not the Cap
Manufacturers like Knapheide and Reading engineer every compartment lock on the service body — but the chassis fuel pocket belongs to Ford or Ram. Nobody owned the gap.
The Zero-Drill Engineering Problem
Consumer billet doors are made for flat pickup beds. The recessed fuel pocket on a commercial chassis is a completely different geometry — and drilling risks voiding the chassis warranty.
The Cost Was Just "Absorbed"
Fleets treated fuel theft like weather damage. A $500 siphoning hit got buried in operating expenses. Without a purpose-built product available, the problem was simply accepted.
The Work Truck Fuel Vault is the industry's first drop-in armored fuel door that uses existing factory mounting points. No drilling. No cutting. No warranty risk.
Who Needs a Diesel Fuel Cap Cover
Contractors
Lock the diesel on your service truck. Stop the overnight siphoning.
Fleet Managers
Cover every diesel fuel cap across your fleet. Real ROI.
Government
City and county diesel fleets need covered fuel caps.
Utility
Diesel utility trucks in remote areas need locked fuel caps.
Upfitters
Add a diesel fuel cap cover to every chassis cab build.
Landscapers
Diesel dump trucks and chipper trucks — cover and lock the fuel.
Chassis Compatibility
Purpose-built for the most popular commercial chassis platforms in the industry.
Ford
Super Duty & Commercial Chassis
- F-350 Chassis Cab
- F-450 Chassis Cab
- F-550 Chassis Cab
- F-600 Chassis Cab
- E-350 / E-450
- F53 Workhorse
Ram
Chassis Cab Heavy Duty
- Ram 3500 Chassis Cab
- Ram 4500 Chassis Cab
- Ram 5500 Chassis Cab
Our Guarantee
Limited Lifetime Warranty
Built to last. Warranted against defects in material and workmanship for the life of the vehicle on which it was originally installed.
30-Day Money Back
Not satisfied? Return within 30 days of receipt for a full refund. No questions asked.
Free Replacements
If your Fuel Vault is defective under normal use within the warranty period, we replace it at no charge.
Frequently Asked Questions
Why do diesel trucks need a fuel cap cover?
Diesel chassis cab trucks carry 40–68 gallons of high-value fuel. The fuel cap is completely exposed from the factory. A diesel fuel cap cover prevents theft, siphoning, and contamination.
Does it work with diesel fuel fillers specifically?
Yes. The Work Truck Fuel Vault is designed specifically for diesel chassis cabs — Ford F-550, F-600, E-350, E-450, and Ram 5500.
Will it fit my diesel truck?
If you have a Ford F-550, F-600, E-350/E-450 chassis cab, or Ram 5500 — yes. The Fuel Vault is purpose-built for these diesel platforms.
Does it require drilling?
No. Bolt-on in 8–15 minutes with basic hand tools.
Does it lock?
Yes — tumbler lock with security torx fasteners.
How much?
From $139.95 with free shipping.
Warranty?
Limited Lifetime Warranty and 30-day money-back guarantee.
Cover Your Diesel Fuel Cap — Starting at $139.95
Armored diesel fuel cap cover for Ford and Ram chassis cabs. Bolt-on. No drilling. Lifetime warranty.
Secure checkout • Free US shipping • No charge until your order ships