Viair 400p Automatic Portable Compressor Review

VIAIR 400p Automatic Portable Compressor Review – Heavyweight Series For Up To 35″ Tires

Let’s face it, air pumps at most gas stations these days are the worst. I can’t tell you how many times I’ve come across pumps that are either out of order, a pain to operate, or cost near a dollar or more to fill up.

Luckily, you can skip the hassle and keep an essential tool nearby like a portable air compressor in the trunk of your vehicle.

Best of all, with a portable air compressor on hand, it doesn’t matter where the nearest gas station air pump is, nor where your current location is.

You could be in the middle of nowhere, hundreds of miles away from the rest of the world, and should you get a flat or need to fill up due to changing road conditions, a portable compressor makes it possible.

With lots of off-road trips planned for my Mercedes G63 AMG, I knew a portable compressor was a must to own! In reality, my tools are my lifeline not to mention, the only things that can get me out of dicey situations in the middle of nowhere.

And so, wanting the best when it came to my tools, I tried to find the ultimate portable compressor. After field testing out the VIAIR 400P automatic from VIAIR’s Heavyweight Series, I believe I’ve undoubtedly discovered one of the best compressors out there.


Quick Highlights:

Portable Tire Compressor Review Viair 400p Automatic

– 12-Volt
– Permanent Magnetic Motor
– Duty Cycle: 33% @ 100 PSI
– Maximum Working Pressure: 150 PSI
– Maximum Amp Draw: 30 Amps
– Ingress Protection Rating: IP54
– Dimensions: 10.87″L x 5.83″W x 7.48″H
– Net Weight: 10.70 lbs.
– Power Cord Length: 8 ft.
– Air Hose Length: 30 ft.
– Gas Station-Style Tire Inflation Gun with 160 PSI Gauge
– Automatic Shut-Off Function Pressure Switch
– Fast Connect Air Hose with Heat Shield
– Vibration-Resistant Diamond-Plate Sand Tray
– Heavy-Duty Dual Compartment Carry Bag
– 40-amp Inline Fuse Holder
– Powered by Dual Battery Clamps
– 3 Piece Inflation Tips Kit
– Runs 40 minutes at up to 40 PSI before needing to be rested
– For up to 35″ Tires
– Convenient tire pressure monitoring while airing up or down
– Permanently lubricated, maintenance-free motor.
– Dual stage air filter with included replacements.


Viair 400p Automatic Portable Compressor Review

Viair 400p Automatic Portable Compressor Box For Up To 35 Inch Tires

Viair 400p Automatic Portable Compressor Specifications

Viair 400p Automatic Portable Compressor Fill Rates Chart

Viair 400p Automatic Compressor Included Portable Travel Bag

Viair 400p Automatic Compressor With Battery Clamps

12 Volt 30 Amps Battery Clamp Viair 400p Automatic Compressor

150 Psi Portable Compressor Viair 400p Automatic

Diamond Plate Bottom With Vibration Free Sand Tray Viair 400p Automatic Compressor

Dual Stage Removeable Air Filters Viair 400p Automatic Compressor

Gas Station Style Tire Inflation Gun Viair 400p Automatic Compressor

Oil Less Design Viair 400p Automatic Compressor Cool Head

Viair 400p Automatic Compressor Air Filter Connected

Viair 400p Automatic Compressor Black High Psi Strength Hose

Viair 400p Automatic Compressor On Off Switch

Viair 400p Automatic Compressor Output Air Hose Connection Seal

Viair 400p Automatic Compressor Rubber Diamond Plate Bottom

Viair 400p Automatic Compressor Tire Pressure Gaguge

Viair 400p Automatic Tire Air Compressor Output Hose Connection

What sets this compressor apart from the rest in my mind is reliability.

The moment you pick the 400P Automatic up you can feel the sturdy build quality. The exterior features a beautiful, near all-metal construction, with limited use of plastic components.

Add in the new black braided high-pressure hose, a dual-stage air filter with replacements, and a permanently lubricated, maintenance-free motor and you’ve got a winner in my book. Of course, things like the automatic shut-off function pressure switch, IP54 Ingress protection rating, and 40-amp inline fuse holder offer a great deal of peace of mind too.

Aside from reliability, the functionality of the VIAIR 400p Automatic compressor left me beyond impressed. Yes, it can fill tires up to 35 inches in size, deliver a max working pressure of 150 PSI, and has a duty cycle of 33% at 100PSI, however, how this compressor achieves those feats is truly impressive.


Viair 400p Automatic Compressor Reviews With Mercedes G Wagon Engine

Battery Clamp Hooked Up Engine Bay Viair 400p Automatic Compressor Reviews

Review G Class With Nitto Ridge Grapler Tires Viair 400p Automatic Compressor

Field Test Outdoors On Dirt Road Viair 400p Automatic Portable Tire Compressor

Mercedes Benz G6 Amg Tire Pressure Read Out Display

Viair 400p Automatic Compressor Review Filling Up Twenty Inch Nitto Ridge Grapler Offroad Tires

With dual battery clamps, for drawing 30 Amps, the process of hooking up this compressor to your car battery is as easy as it gets. Best of all, both the air hose and battery cable line feature an extremely generous length. There’s no need to tug or position things just right to maximize the length of the hose/line needed to fill up your tires. Just hook it up, and the 8ft power cord and 30ft air hose will freely extend across your entire vehicle.

With the car turned on, and the VIAIR 400P automatic compressor started, the operation is incredibly quiet. I was expecting a rather loud buzzing noise, but to my surprise, it was softer than the Mercedes V8 AMG motor running.

For ease of use, VIAIR has included an excellent gas station-style tire inflation gun with an accurate 160 PSI Gauge. For me, it makes me feel like I’m back at the car dealership in the service bay with a professional tool in my arsenal. For operation, the tire inflation gun works as you’d expect, squeeze the trigger down to fill, and release fully to get a pressure reading. Continue until the desired pressure is reached.

Now, unlike other portable air compressors out there, this one is as the name implies automatic. That doesn’t mean it fills your tires up automatically or to a certain PSI on its own. Instead, it means that you no longer have to run from the compressor to the tire and back to fill up the tire. In other words, turn on the compressor once, fill up all your tires, and turn the compressor back off. That’s it; it’s as simple as it gets.

While the VIAIR 400P automatic portable compressor weighs a little over 10 pounds, VIAIR has also included a tremendous vibration-resistant diamond-plate sand tray. Needless to say, it doesn’t hop around during operation; instead, it stays exactly where you place it.

For run and fill times, the VIAIR 400P automatic will operate for 40 minutes at up to 40 PSI before needing a quick break. When it came to filling up, my Nitto Ridge Grappler tires up plus 10 PSI it only took around 30 seconds or less. For me, that’s fast! Should you be looking for specific fill, times check the chart above in the photos for a more accurate dataset.

Overall, it doesn’t get any better than this compact and ultra-portable compressor. From reliability to functionality, VIAIR has given the 400P automatic compressor exceptional attention to detail. In return, you can bet there will always be one in my trunk while taking the road less traveled.


VIAIR 400P-Automatic Function Portable Compressor



Viair Logo Special Feature


Be A Gentleman
Share This Now
Greatness For Men
“Pride is the prevailing spirit of superior men.”