What size air compressor for tires?

[tmaxx]

I've got a 29' class c rv with dual tires on the rear. I have it covered for the winter. I noticed today that the outer back tire has only 30 psi. I had a small compressor (3gallon, 100psi) which I carried out to the rv to air up the tire. It took about 15min just to raise it 10psi. I think the compressor is just too weak. I want to buy a new one that I can use when the tires get low. I want one that is not too bulky. Can someone suggest what size I need for airing up my rv tires?
Thanks

[Mr_D]

Try raising a 367/70 tire from 100 to 110 if you think your compresser is weak!
We have a 120 V Coleman 150 psi unit and it will do it, but takes lots of time and several rest periods.
For the OP's use it wold be ideal though.

[tmw188]

There are some good reading on older posts if you do a search for air compressors in the General Motorhome Discussions


iPad using iRV2 - RV Forum

[twinboat]

It could be that the air is leaking out almost as fast as your putting it in.

It shouldn't be down to 30 psi, unless something is wrong. The higher the pressure the faster the leak.

That goes with all tires. Even the tire manufactures say " More then 2 psi per month, get them checked. "

[tkcas01]

I have 22.5" tires that need to be inflated to 115# rear and 105# front. For years I have had a Porter Cable compressor and it just wasn't up to the task. I just purchased this unit and wish I had found it years ago. Got them all aired up in record time with minimum fuss.

VIAIR Corporation - 400P Compressor (P/N 40043)

[pasdad1]

Oops, my post came in too late....as others have said Viair is popular

[tkcas01]

Originally Posted by pasdad1

Oops, my post came in too late....as others have said Viair is popular
Attachment 119582

You have good taste, sir! I never thought a 12V compressor could do what this one does.

[JerryP]

I bought my VIAIR Corporation - 400P-RV Compressor a couple of months ago. Works great on airing up my tires. I would recommend this unit. The RV version has extended hoses and several features that help with RV applications. One nice feature is the automatic cutoff. When you stop airing the tires, the compressor will shut off. Restart airing and it kicks in again. Most compressors have an on-off switch that forces the compressor to run all the time.

I put 85 to 90 lbs in my tires. Not sure how it would do if you had to put 120 lbs or more. It has an odd Cut-in pressure feature at 120 lbs. If you stop the compressor while the pressure is above 120 lbs, it will not restart. You have to air your tire down to 115 and start again. This might be an issue on some of the higher pressures used on diesel pushers.

Regards,
Jerry 2013 Newmar Bay Star

[coachmanjay]

If your ties only need 80 psi look into the Viair 88P and their 6 ft extension, will do the job at a quarter of the cost

[Mr_D]

Yep, I really should invest in one of the Viair units!

[JerryP]

Viair makes a 400P-RV and recently offered the 450P-RV.
The 400P has a 33% duty cycle. 20 minutes on and then 40 minutes off.
The 450P has a 100% duty cycle. That means that it can run continually. I purchased the 400P since it has a much higher air flow rate. In normal air up situations, it should never take more that 20 minutes to do the job.

These compressors are heavily used in 4-wheel drive applications. 4 wheelers air their tires down to 10 lbs to run in sand and mud. After the off road run, the wheeler then airs all the tires up to full pressure. They are designed for heavy usage.

Jerry 2013 Newmar Bay Star

[Mr_D]

I see what you mean about the 400 VS 450. The 400 is rated for the 33% duty cycle when at 100 psi so it would be a longer cycle at lower pressures. Probably enough under most circumstances even with our large front tires at 110 psi.

Anything more than just adding 10 psi is going to need a tire shop truck anyway.

[mc8404]

Just as another option, the Porter Cable at the link below is what I purchased. It fits nicely in the front storage compartment of our Class C, can quickly inflate the tires to 90lbs fairly quickly, and it's quiet.

It's also fairly inexpensive at under $100.

Robot Check

[mwwade]

Good info!!