It depends on how much rust your vehicle has. Take a look underneath at the frame, wheel wells and brake lines, then pick the closest match:

• New vehicle (no rust, usually 0–1 year old): BOSS Wax^® & Oil, or Original Oil Undercoating.
• Light rust (surface rust, metal still solid): BOSS Wax^® Hybrid, NHOU^® V3, or Original Oil Undercoating.
• Heavy rust (flaking, scale or pitting): Rustoration^® to convert the rust, then Original Oil Undercoating in Black.

Not sure? Use our product guide or contact us.

• NHOU^® Original Oil Undercoating is our flagship. It penetrates rust, displaces moisture and blocks oxygen. Available in Clear or Black, DIY or professionally applied.
• NHOU^® V3 combines the penetration of petroleum, the grip of wax and the moisture resistance of lanolin in one drip-free formula.
• BOSS Wax^® & Oil is a two-stage system made only for new, rust-free vehicles, with a non-tacky black finish.
• BOSS Wax^® Hybrid is a semi-permanent, matte-black protection for vehicles with light rust.

BOSS Wax^® and Hybrid are professionally applied only and come with a lifetime, transferable warranty when applied by an NHOU^® Authorized Applicator.

Both give the same trusted protection. Black adds a biodegradable tint that gives the underbody a clean, black finish. Clear leaves surfaces looking natural.

No. BOSS Wax^® & Oil and BOSS Wax^® Hybrid are applied only by NHOU^® Authorized Applicators, which is what makes the lifetime warranty possible. Find an applicator near you. Applicators interested in offering them can contact us.

NHOU^® Storage Shield is rustproofing and undercoating with peppermint, made for vehicles and equipment going into storage. It seals off oxygen to help prevent rust and protects electrical connectors, switches and motors.

For rodent protection, add NHOU^® Mouse-Out Pouches. The NHOU^® Mouse-Out Kit includes both: Storage Shield for corrosion protection and Mouse-Out Pouches for rodent protection. Learn more about Storage Shield.

A military specification (MIL-SPEC) is a standard created by the U.S. Department of Defense for the design, production and performance of materials and products the military uses. It helps ensure reliability and consistency. Learn more about MIL-SPEC.

Either works with Original Oil Undercoating and V3. An NHOU^® Authorized Applicator has the lift, equipment and training to reach every seam and cavity. Find an applicator. If you prefer to do it yourself, our DIY Kit gives you pro-level results at home. BOSS Wax^® and Hybrid are professionally applied only.

NHOU^® is atomized under high pressure, pushing the product deep into the seams, cracks and crevices where corrosion starts. Once applied, it removes moisture from those areas, adheres strongly to the surface and stays active with excellent creeping and self-healing abilities.

It depends on the size of your vehicle and its condition. Contact us and we’ll recommend the right size for your vehicle.

Check with your applicator, since each shop is independently owned. If your vehicle has heavy mud or flaky rust, it should be pressure washed, especially around the frame and wheel wells, ideally a day before service.

Note: Prep time may require scheduling and could involve additional costs.

Yes. Our oil-based formula chases water, so it can be applied on damp days, and moisture can even help it penetrate tight seams. Unlike products that mix with water, NHOU^® displaces it.

Note: Dry conditions are ideal, and application during heavy rain is not recommended.

Treat it in two steps: convert the existing rust with NHOU^® Rustoration^®, then seal the underbody with Original Oil Undercoating in Black. See the heavy rust plan.

If metal is rotted through or structural parts feel soft, have a mechanic inspect the vehicle first. Undercoating protects metal; it doesn’t repair it.

NHOU^® Original Oil Undercoating is formulated to be low-drip. In rare cases of heavy application, minimal dripping may occur, and it cleans up easily with Dawn^® dish soap or Simple Green^®.

Want drip-free? NHOU^® V3 is a drip-free hybrid formula.

You may notice some smoke and odor from under the vehicle the first time it’s driven. This comes from a small amount of overspray on the exhaust system. It is harmless and should stop quickly.

After a BOSS Wax^® application, wait at least three weeks before using a high-pressure undercarriage wash.

With NHOU^® Oil Undercoating, undercarriage washes should generally be avoided, but cleaning the undercarriage before your next service is recommended.

Keep in mind: most car washes recycle water, which often holds road salt, and high-pressure jets can force salt back into body cavities.

Driving conditions vary, but we recommend an annual NHOU^® Oil Undercoating application for consistent protection. Think of it as affordable insurance: a small yearly investment in long-term value, safety and rust protection.

No. NHOU^® products do not prevent scratches, peeling paint or stone chips. Repair exterior paint damage promptly to prevent surface rust.

No. NHOU^® is non-conductive and will not harm electrical connections. Make sure all connections are made before applying.

No. A federal law called the Magnuson-Moss Warranty Act says a manufacturer can’t void your warranty just because you used an aftermarket product, unless they can prove that product caused the problem.

Rustproofing helps your vehicle last longer, which is the whole point of a warranty. If a dealership tells you otherwise, ask them to put it in writing.

NHOU^® BOSS Wax^® and BOSS Wax^® Hybrid Lifetime Transferable Nationwide Warranty. When a factory-trained, certified applicator applies Mil-Spec BOSS Wax^® to your vehicle, the warranty covers the full life of the vehicle. You can bring it to any certified applicator for inspections and complimentary touch-ups.

Touch-ups that need an overnight stay because of large repairs, such as major accident damage, may fall outside the warranty and could involve charges.

Download the warranty PDF

• Shop online for U.S. delivery.
• Find a retail store to buy in person.
• Outside the U.S.: Canada, Europe and Germany.

Use our applicator locator to find an NHOU^® Authorized Applicator and schedule service. Retail stores sell products but don’t apply them, so use the applicator locator if you want it done for you.

Yes. Shipping is free on U.S. orders over $100.

Validating your address confirms it for accurate tax and shipping. Click Validate Address before you enter your card details. We can’t ship to PO Boxes, so please use a physical street address.

NHOU^® Oil Undercoating is a highly refined mineral oil that is nonhazardous and solvent-free, with natural “green” corrosion inhibitors derived from plant and animal fats.

Unlike hard coatings, it stays soft, so it migrates and creeps into hard-to-reach areas like rocker panels and door cavities. It displaces moisture, blocks oxygen and forms a lasting, self-healing barrier. Even light surface rust gives the oil something to grip, much like prepping a surface before painting.

The bulk flash point of NH Oil Undercoating^® NAS is 425°F.

Safety Data Sheets are on each product page under SDS Info. If you can’t find the one you need, contact us.