Dynamax Isata 5 Fuel Cap Cover & Locking Fuel Door
The RV Fuel Vault is an armored, patent-pending locking fuel door purpose-built for the Dynamax Isata 5 and its Ram 5500 Super C chassis. Stops fuel theft, siphoning, DEF contamination, and vandalism on your $300k+ motorhome \u2014 the part the factory forgot.

The Problem
- ✖The Ram 5500 chassis under the Isata 5 ships with an exposed diesel fuel cap and an exposed blue DEF cap — both sit unprotected on the driver side
- ✖50–80 gallons of diesel per side plus a full DEF tank sitting in the open at every campground and truck stop
- ✖Dynamax owners frequently report fuel-theft near big-city truck stops — the Isata 5 is a known siphon target
- ✖A single contaminated DEF fill can total the emissions system and strand the motorhome ($8k–$20k+ in repairs)
- ✖Factory fuel caps finish with a cheap plastic look that clashes with the Isata 5’s premium fit and finish
The Solution
- Armored, tamper-proof 3/16″ fiber-filled polymer fuel door — direct fit on Dynamax Isata 5 fuel door area
- Patent-pending (U.S. Application 19/632,042) keyed lock — same key opens diesel fuel door, passenger-side door, and DEF tank cover
- Bolt-on install in 8–15 minutes — zero modifications, zero warranty-impacting drilling
- Full factory-finished look: replaces the ugly exposed green diesel and blue DEF caps with matching armored doors
- Stops fuel theft, siphoning, and DEF cross-fills — one armored shield, three problems solved
- Single Door $84.95 • Set of 2 $149.95 • 3-Pack with DEF cover $224.95. Limited Lifetime Warranty. Made in Sarasota, Florida.
Pre-Order Today — Starting at $84.95
Single Door, Set of 2, or 3-Pack · Free shipping · Limited Lifetime Warranty · 30-day guarantee
Pre-Order NowProudly Made in the USA · Patent Pending 19/632,042
