portable air compressor

I think it depends on your intended use. If you are a full timer and this will be your primary “devise” for airing up your tires, then a 120v pump like the $100/ 6 gallon Porter Cable unit is good (the 150 PSI red pancake compressor that many use). Larger units (like what GordonThree posted), works better, but takes up more storage.

If you check your air at home and only carry a compressor for a rare need to “top off” a low tire, then a good 12V pump will be adequate (and take less storage space). In either case, give it a test before you actually need it.

I carry the Porter Cable compressor, because I air up a towed off road vehicle. It doubles as an emergency compressor for the RV, but I wouldn’t carry it if not for the jeep.

BTW – if you have a DP with air systems, an alternative is to tap into that and carry long enough hose to get to all tires.

Mile High wrote:

diplomatdon wrote:
Hi, drove truck for 43 years and all I ever used was a 50' airline and the truck air system. Idle engine to 12001500 RPM. Works, lighter and less expensive. Just my 2 cents. Don

My onboard air only puts out 100-110 at best. I can't air my 120 psi 22.5 tires.

Same on my coach, which is why I recommend a 110 V pancake compressor that develops 150 psi.

diplomatdon wrote:
Hi, drove truck for 43 years and all I ever used was a 50' airline and the truck air system. Idle engine to 12001500 RPM. Works, lighter and less expensive. Just my 2 cents. Don

My onboard air only puts out 100-110 at best. I can't air my 120 psi 22.5 tires.

Hi, drove truck for 43 years and all I ever used was a 50' airline and the truck air system. Idle engine to 12001500 RPM. Works, lighter and less expensive. Just my 2 cents. Don

carp65 wrote:
Looking for thoughts and considerations for an AIAir 4000P 12V
air compressor capability to air 22.5" tires on a Class A
motorhome. All information and comments will be appreciated

I don't know about that model, but I have purchased several smaller 12 volt compressors, and they just don't get the job done. They are okay to have on board for emergencies, but if you get a tire that needs 30 or more pounds, you may be setting there for 45 minutes with that compressor running. I have a smaller 110 volt compressor that I bought from Lowes. It has a 150 psi cut off. Yeah, it takes up some space, but it gets the job done.

I had a large Viair system on my truck and camper. It was useable for my 17 inch tires on the dually, but when I went to a coach with 22.5 inch tires, I knew the Viair system would not be adequate. I went to a 110 Volt pancake compressor that produces 150 psi. I am happy with it.

12 volt compressors can work on 22.5 inch tires.. provided you don't mind running it all day and part of tomorrow

I carry a 6 gallon 150 PSI job from Crafstman for my tires 120 volt and still takes a while.

Anyone own a Smittybilt 12v compressor? They seem to have the best cfm and duty cycle among tiny compressors.

I have a Ingersoll 1 gallon that fits well in a tool box. It was like $50 from Amazon. Just turn on the inverter and fire it up.

CFM at 80 psi is kinda lacking however.

Biggest advantages to AC powered compressor is 100 pct duty cycle and extension cord for AC is a lot better than a long hose on a DC unit.

JMHO

From the Vair web site, the Viair 400P has a 33% duty cycle at 100psi. It also lists the following example fill rate for an off road tire:

35? x 12.5? Fill Rate
0 to 30 PSI 5 min. 20 sec. (± 15 sec.)
15 to 30 PSI 2 min. 45 sec. (± 10 sec.)

This tire is significantly smaller than a 22.5 wheel where the tire can be almost 46" in diameter. The fill rate drops to 1.19 CFM at 100 psi from 1.86 CFM at 30 psi. Since the duty cycle is 33% you will need to give it a rest to let it cool off. It also does not have a tank.

I used a Viair 450 as a replacement compressor for my air leveling system. The 450 is a continuous duty compressor at 100 psi. After installing it I exercised pretty hard and had it running to 15 minutes continuously leveling to coach from an empty air bank. The compressor got very hot, hot enough to burn you.

To top off our tire we bought the compressor for Lowes:

Fini 1.2-Gallon Portable Electric Hot Dog Air Compressor

This little compressor works great for topping off tires. It is a lot smaller than a pancake compressor. I have also used in the field to run nail/brad and staple guns when my big compressor was not available.

Why not just go to a 110V compressor? This Porter Cable produces 2.0 cfm at 90 psi and 3.0 cfm at 40 psi, whereas your Viair 400P only produces 1.28 cfm at 90 psi and 1.75 cfm at 40 psi. Those big tires take a lot of volume in addition to pressure.

Porter Cable