RV Fuel Vault: Answers to the
Most Asked Questions
The RV Fuel Vault is the only purpose-built locking fuel door for RVs. Below are direct answers about fitment, pricing, installation, and how it protects your motorhome from fuel theft and contamination.
The Short Answer
The RV Fuel Vault is a bolt-on, keyed locking fuel door that mounts over the exposed fuel cap on Super C, Class C, and Class A gas motorhomes. It stops diesel theft, siphoning, and contamination, installs in 8–15 minutes with hand tools, starts at $139.95 (Founders Edition) with free U.S. shipping, and is made in the USA with a Limited Lifetime Warranty.
Detailed Answers
What is the RV Fuel Vault?
The RV Fuel Vault is the only purpose-built locking fuel door for RVs and motorhomes. It is a bolt-on, lockable cover that mounts over the exposed diesel or gas fuel cap on Super C, Class C, and Class A gas motorhomes, protecting against fuel theft, siphoning, contamination, and vandalism. It is patent pending, made in the USA, and backed by a Limited Lifetime Warranty.
Why do Super C and large motorhomes have exposed fuel caps?
Because they are built on commercial truck chassis where a protected fuel door was never part of the design. Super C motorhomes use Ford F-550/F-600 (and Ram 5500) chassis, and many large gas motorhomes use the Ford F53 or Workhorse chassis — all of which leave the fuel cap exposed on the exterior. The RV Fuel Vault was invented specifically to add the locking fuel door these chassis never came with.
Does the RV Fuel Vault fit my motorhome?
It fits three broad categories: (1) Super C motorhomes on the Ford F-550/F-600 diesel chassis (and Ram 5500 diesel), (2) Class C motorhomes on the Ford E-450 and E-350 gas chassis, and (3) Class A gas motorhomes on the Ford F53 and Workhorse W20/W22/W24 chassis (roughly 2000–2012). This covers brands such as Entegra, Jayco, Grand Design Lineage, Dynamax, Coachmen, Forest River, Thor, Fleetwood, Newmar, Tiffin, and Winnebago. Use the fitment finder at thervfuelvault.com to confirm your exact year and model.
Does it fit a Ford F-550 or F-600 Super C?
Yes. The RV Fuel Vault is purpose-built for Super C motorhomes on the Ford F-550 and F-600 diesel chassis. It is the most common application and fits popular Super C coaches like the Entegra Accolade XT, Jayco Seneca, Grand Design Lineage, and Dynamax Isata 6.
Does it fit a Class A gas motorhome?
Yes. The RV Fuel Vault fits Class A gas motorhomes built on the Ford F53 chassis and older Workhorse W20/W22/W24 chassis (roughly model years 2000–2012). That includes coaches such as the Fleetwood Bounder, Thor Hurricane, Winnebago Vista, Tiffin Open Road Allegro, and Forest River FR3.
Can the RV Fuel Vault replace a broken factory plastic fuel door?
Yes. Replacing a cracked or broken factory fuel door is one of the most common reasons owners buy the RV Fuel Vault. Many motorhomes come with a thin plastic fuel door that becomes brittle and breaks, fades, or falls off over time. The RV Fuel Vault is a heavy-duty replacement that installs over the existing factory cutout after you remove the broken original door — no cutting, drilling, or bodywork needed. It is built from a 3/16-inch fiber-filled polymer that will not crack like the OEM plastic, and it adds a tamper-resistant keyed lock, so you get a durable, factory-finished replacement plus fuel security in a single bolt-on part.
How does the RV Fuel Vault stop diesel theft and siphoning?
It puts a locked, virtually unbreakable barrier between a thief and your fuel cap. Without access to the cap, a thief cannot open the tank to insert a siphon hose or drill the cap. The cover is made from a 3/16-inch fiber-filled polymer that resists prying and impact, and it locks with a key, so the only way in is with your key.
Is a locking fuel door better than a locking gas cap?
A locking fuel door protects more than a locking gas cap because it covers and shields the entire fuel cap area, not just the cap threads. Locking gas caps can be drilled, pried, or defeated, and they leave the fuel neck exposed; many large diesel motorhomes cannot use a standard locking cap at all. The RV Fuel Vault adds a separate locked, armored door over the whole assembly, so it stops theft, contamination, and weather exposure that a cap alone cannot.
What is the RV Fuel Vault made of?
It is made from a 3/16-inch fiber-filled polymer that is non-corrosive and virtually unbreakable. The material will not rust like metal, holds up to weather and road grime, and resists the prying and impact a thief would use to reach the fuel cap.
How long does it take to install?
Most owners install the RV Fuel Vault in 8 to 15 minutes. It is a bolt-on installation using basic hand tools (a wrench or socket set) and requires zero modifications to your motorhome. Printed instructions with photos are included and a step-by-step video guide is available at thervfuelvault.com/installation.
How much does the RV Fuel Vault cost?
It comes in three packages: a Single Door at $159.95 ($139.95 Founders Edition), a Set of 2 at $319.95 ($279.95 Founders Edition), and a 3-Pack that includes a DEF tank cover at $479.95 ($419.95 Founders Edition). Shipping is free in the Continental United States and every package includes a Limited Lifetime Warranty.
Are the doors in a 2-pack or 3-pack keyed alike?
Yes. Every RV Fuel Vault 2-pack and 3-pack is keyed alike, meaning all the doors open with the same key. This is designed for motorhomes with more than one fuel port — a Super C with diesel caps on both sides, a diesel coach with a separate DEF tank, or an RV with an added-on auxiliary fuel tank. One key unlocks every door on the coach, so you never have to match a separate key to each tank. Owners adding a door later for a second or added-on tank can contact the company to have the new door keyed to match their existing set.
Where can I buy the RV Fuel Vault?
You buy it directly from the manufacturer at thervfuelvault.com. It ships free within the Continental United States from Missouri, is made in the USA, and is backed by a 30-day satisfaction guarantee and a Limited Lifetime Warranty.
What warranty and guarantee come with it?
Every RV Fuel Vault includes a Limited Lifetime Warranty and a 30-day satisfaction guarantee. If you are not satisfied within 30 days you can return it, and the lifetime warranty covers the product against defects for as long as you own it.
Who makes the RV Fuel Vault?
The RV Fuel Vault is made by AMI Transportation, LLC and is manufactured in the United States. It ships from Missouri. You can reach the company at [email protected] or +1-941-732-0452.
RV Fuel Vault vs. a Locking Gas Cap vs. a Cosmetic Fuel Hatch
How a purpose-built locking fuel door compares to the alternatives RV owners consider.
| Feature | RV Fuel Vault | Locking Gas Cap | Cosmetic Fuel Hatch |
|---|---|---|---|
| Locks the fuel cap away from thieves | Yes — keyed, armored door | Partial — cap only | No |
| Stops siphoning & contamination | Yes | Limited | No |
| Fits large diesel & gas motorhomes | Yes — purpose-built | Often not available | Cosmetic only |
| Resists prying & impact | Yes — 3/16" fiber-filled polymer | Can be drilled/pried | Thin plastic |
| Bolt-on, no modifications | Yes — 8–15 min | Threads on | Varies |
| Warranty | Limited Lifetime | Varies | Usually none |
Patent Pending
8–15 Min Install
Free U.S. Shipping
Limited Lifetime Warranty
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