I regularly go off-roading in California's deserts and wanted a reliable way to add pressure to my tires when returning to the pavement, and to reinflate tires after a repair. I purchased this compressor in 2010 after my cheap, barely adequate $25 "tire inflator" from a department store chain stopped working. I have had zero problems with my Viair.

Uses:

In addition to the uses above, I use the compressor every couple of weeks to top up one of my tires that has a slow leak. I just used it to quickly top up the tires on my wife's van. I have also used it to inflate my kid's wading pool via an extra attachment that came with our bicycle pump.

Pros:

Well made and reliable

Easy to connect to the red battery terminal and ground via the alligator clips

Positive latching on to the tire stem

Pretty fast inflating of even large tires

Consistent readings from the integral tire gauge

Packs up into a relatively small package that can stay in any vehicle 24/7

Carrying case is handy and makes storage easy

Cons:

Gets warm after a couple of tires and needs to cool off before packing it up

The coiled hose offers a lot of resistance, making reaching the last tire a struggle

Getting the compressor back into its case takes a little work

Bottom line:

Good piece of gear at a fair price point. An additional bonus is that I can forever skip the quarter-fed, nasty gas station air stations that seems to pump as much moisture into my tires as air.

I was wanting a better quality tire inflator to carry in my Travel Trailer. It had to easily inflate my trailer tires that are rated for 80psig. I read over the reviews of several inflators and decided on the 300P. Put it to the test yesterday. I am very pleased. Had no problem handling the 80psi tires. Pumped one that was at 70 psi up to 80 in about 65 seconds. The battery clips are plenty large enough to grab onto a battery post connector. My trailer batteries are located front underside of my 34 foot 5th wheel center compartment.

With electric wire and coil air hose, I reached tires with no excessive stretching. The air hose to valve stem clamp is very good and tight. No air loss and would be much easier than the screw on fittings others come with. This unit also has the "Air release" feature to let out excess pressure. The air gauge is a good quality. The pump is much quieter than I thought it would be. Comes with a very good carrying bag that has room to include any special fittings you may need. I did have my trailer plugged into electric power when using the inflator. The write up on it stated to have vehicle running while using. This is to give the 12V a little extra boost. This is understandable. The in-line electrical fuse would make it very easy to replace fuse if needed. I will be buying an extra fuse to carry just in case.

This is a serious work horse. My hotdog compressor is rated for 150psi but can't inflate my 110psi fifth wheel tires! This little unit brought all four tires up to the recommended pressure in about ten minutes. It runs on 12volt power with big clamps directly to the battery so it works anywhere. It clamps onto the valve stem so you don't need bionic fingers to hold it on. It does get hot, but not dangerously. Highly recommend this for RV travel and nearly unlimited other uses.

I’ve had my 300P since 2014 and have used it regularly to air up 235/85 R16 tires from 15 to 35 psi after coming off the trail, as well as after puncture repairs. The compressor itself has been very dependable and has never let me down.

The weak point is the inflator setup, especially the hose, chuck, and gauge. The gauge was never very accurate, but I always carried a stick gauge, so that was not a major issue. Mine came with the older yellow nylon hose, which is very stiff unless the weather is quite hot. I would not want to use it in cold conditions. It also feels a bit short for longer-wheelbase vehicles. I used it with a Toyota Prado 95 and a Defender 110, and it was sometimes difficult to uncoil the hose without pulling the compressor over or dragging it enough to disconnect the battery clips.

More recently, the chuck has also started to become troublesome. It now takes a fair amount of pressure to hold it on the valve stem without air leaking around the valve. That has become the most annoying part of using it.

I’ve also kept the original Styrofoam packing inserts inside the storage bag to give the compressor a little extra protection when it rides in the back of the truck

Overall, the compressor itself has been durable and reliable for more than a decade, but the hose, chuck, and gauge are the weak links. It looks like the newer 300P kit now comes with a braided hose, which may solve some of these issues. I will probably replace my hose/chuck/inflator assembly with a braided setup soon.

If I were reviewing the compressor itself, I would rate it highly. If I were reviewing the complete package, I would say the compressor is excellent but the accessories leave room for improvement but can get the job done.

I purchased this air compressor to air up my Jeep 33” tires after going off-road. The Viair compressor is relatively quiet and fill speed is very good. I wanted to go with a slightly stronger (faster) model, but I needed to stay under 40 amp draw. The bag, hose and fill is top quality - much nicer than the off brand units. Highly recommend.

This works great. I have 33" tires and I'm able to air up from 15psi to 35psi in less than 10 min for all 4 tires. And that is just using 1 hose. If I had a 4 hose setup, I think it could handle that also. Bat is a bit larger than all the gear which allows for added extras so you keep all the air stuff together. A great buy

the unit works perfectly for inflating tires.

I use this on my old pickup that has aluminum wheels and being 10 years old tends to lose air. I could replace tires and maybe that would solve it (but the tires are in very good shape) and then after replacing them find it is the wheels... in either case not worth investing in... easier to use this [excellent] 12v tire pump. will also move it to the RV when that is being used (just in case there is a problem).

By all means, this unit pumps up the 16 or 18 inch tires from 25 or 26 lbs to 44 lbs pretty quick. Nice feature is the pressure gauge is near the inflation end... easy reading. Comes with all the ends you might need... if you are looking at a portable 12v air compressor... look closely at this one

I bought this portable pump about 3 years ago for fixing flats on the road. I keep it stowed in my truck under the back seat. It has worked very well. Its convenient enough that I use it at home to maintain tire pressure in all of our vehicles. Its been a reliable tool with good build quality.

Good to know:

The pump gets hot for a bit, so you need to let it cool before re-stowing it.

If you have a lifted truck the power cables might not allow the pump to reach the ground.

The pressure gauge only reads when the unit is off. That makes for a little back and forth when you want to check progress. Not hard to let out excess pressure, though.

Die Gerätetasche hat Stockflecken und stinkt intensiv nach Chemie. Trotz mehrmaligem Waschen und Lüften ist der Mangel nicht zu beheben.

Easy to use. Inflates tyres quickly. Good carry bag for neat storing.

Buen producto

Awesome compressor I’ve been using this for my Jeep Cherokee on 33s for a couple years now it always works and it’s pretty fast for 33s

Mucha potencia para el tamaño de compresor, levanta la llanta de una camioneta pick up desde el piso sin ningún inconveniente en cuestión de minutos.