VIAIR 400P-RV (40047) 12V Portable Tire Inflator with RV Inflation Gun

If you’ve ever had a low tire ruin your plans—or you’ve needed air for an RV setup at the worst possible moment—this is the kind of tool you keep close. The VIAIR 400P-RV (40047) is a portable, 12V tire inflator kit built around quick, on-the-go pressure top-ups.

It’s also one of those purchases where the details matter: a tire pump is only as useful as its fitting method and how easily it operates when you’re standing next to the vehicle. The 400P-RV’s RV inflation gun and 90-degree chuck approach the job with fewer awkward angles, and the kit is described as heavy duty for tire inflation up to Class C tires.

Key takeaways

The biggest reason to look at the VIAIR 400P-RV is its focus on practical inflation: it’s designed as an automatic portable compressor kit for vehicle tires and RV-related inflation. On paper, it’s aimed at people who want something more than a basic inflator—especially if you’re dealing with RV tires or you frequently need to add air.

That said, it’s not a universal “set it and forget it” gadget in every scenario. Like many portable 12V compressors, the real-world experience depends on tire size and your power setup in the vehicle, and you’ll want to confirm your exact tire requirements before relying on any inflator as your only backup plan.

What it is and what it’s for

This product is a portable air compressor kit for tire inflation, positioned as a 12V pump. The listing specifically mentions an RV inflation gun plus a 90-degree chuck, which is a useful combo if you’ve dealt with hard-to-reach valve stems or you’re trying to keep things aligned while inflating.

In everyday terms, it’s the kind of tool you’d use when: - You spot a slow leak and need to restore pressure before driving far. - You’re preparing an RV trip and want to check tires before departure. - You need to top off pressure while traveling rather than searching for a nearby station.

Where it shines

There’s a clear “use it, don’t baby it” angle here. The kit is described as heavy duty and rated at 150 PSI, with support for inflation up to Class C tires. If your typical needs involve RV tires or you want a compressor that can handle more demanding tire categories than the smallest inflators, this is the lane it’s aiming for.

The RV inflation gun and included alligator clips (as noted in the product name) also suggest a setup that’s meant to be flexible in how you power and connect the inflator.

What to watch before buying

Portability is great, but it comes with tradeoffs. Two things to consider before you commit:

First, verify that your specific tire type and use case match what the kit is intended for. The listing says it’s “up to Class C tires,” but that doesn’t automatically cover every tire situation.

Second, check how you plan to connect and run it in your setup. Because this is a 12V inflator, your vehicle’s power access and the way the kit connects matter. If you’re expecting it to behave like a home compressor, it may feel more “on-the-go” than “always ready.”

Tech specs (as listed)

• Name: VIAIR 400P-RV - 40047 Tire Inflator Portable Air Compressor with RV Inflation Gun
• Type: 12V portable tire inflator / portable air compressor kit
• Capacity: up to Class C tires
• Rating: 150 PSI
• Chuck: 90 degree chuck
• Power/connection: alligator clips mentioned in kit name
• Format: automatic portable compressor kit

Mini FAQ

Is this mainly for RV tires or regular car tires?

Based on the listing, it’s positioned for tire inflation up to Class C tires, and it includes an RV inflation gun. It can still be used for general tire inflation needs, but the RV-oriented parts are the hint about its primary target.

What does the 90-degree chuck help with?

A 90-degree chuck is useful for reaching and aligning the valve connection at tighter angles. It’s the kind of design detail that can save you from fighting the hose position while inflating.

What’s the practical advantage of “automatic” here?

“Automatic” in this context implies you don’t have to constantly manage the compressor the same way you would with more basic manual inflators. Exact behavior isn’t detailed in the provided info, so it’s worth confirming what the automation means for your intended use.

Does it work only when powered from the vehicle?

The product is described as a 12V tire pump/compressor, so it’s designed around a vehicle power setup. If you don’t have reliable access to 12V power in your situation, you may want to reconsider.

Should you buy it?

Buy the VIAIR 400P-RV (40047) if you want a portable 12V tire inflator kit that’s clearly aimed at heavier tire needs, including up to Class C tires, and you like the idea of an RV inflation gun plus a 90-degree chuck for easier valve access. It’s a strong pick if you’re the type of owner who checks tire pressure before a trip and wants a compressor you can deploy on the spot.

Not the best choice if you only need an occasional, low-intensity top-off for very small tires and you want something simpler and lighter. If you don’t plan to use RV-specific inflation features—or you need a setup that doesn’t rely on 12V power—this kit may feel more than you need.

Final verdict

On balance, this one makes sense for buyers who prioritize readiness and more capability than a basic inflator, especially for RV tires. Just make sure your tire category and connection plan match what the kit is described to handle, because that’s where “portable and heavy duty” either pays off—or falls short.