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S-n-L · 02-09-2015, 11:03 PM

Hello everyone,

I finally gave in to find an easy solution to topping off my tires without turning on the engine. I have been reading good reviews about the viair 12 volt portable compressors and wanted to give them a try. The one problem was, I could not decide which of these two models would work best so I purchased both to test and would return the one that does not perform best.

Here are the specs for the two models:

Model 400 P-RV Automatic-
Duty cylce = 33% (can run for 10 minutes then must rest for 30 minutes)
CFM = 2.54 CFM
Advantage = greater CFM
Disadvantage = shorter duty cylce
Max amp draw = 30 amps

Model 450 P Automatic-
Duty cycle = 100% (can run continuously without stopping)
CFM = 1.66 CFM
Advantage = 100% duty cyle
Disadvantage = Lower CFM
Max Amp draw = 20 amps

(note on amp draw and compressors: the more efficient the compressor is the lower the amp draw is, so the lower number here is better than a higher number)

To be clear, I will never use this compressor to fill a flat RV tire, only to top them off with 5 to 10 psi. I needed something to reach 120 psi without struggling. My main concern and question with the 450P was would it take a ridiculous time period to top off a tire compared to the 400P RV.

Method:

I purged one tire to 117 psi and clocked the time to fill this tire to 122 psi. The ambient temperature was 75 degrees Fahrenheit

The 400 P-RV took 1 minute, 35 seconds.
The 450P took 1 minute, 55 seconds.

As it turned out the difference in time was not too significant. My choice was to keep the 450P in order to have the 100% duty cycle and will be sending back the 400P-RV.

I was particularly curious about the performance of these two models when I first watched a video recommending the 400P-RV from the RV GEEKS. I wonder if they ever tested the 450P model.

I hope this information is helpful to some and look forward to hearing your input and opinions on this subject.

Stuart

spinn · 02-09-2015, 11:21 PM

Nice write up Stuart. I bought the 450 as well

USCGIS · 02-10-2015, 07:09 AM

I'm in the process of ordering a Newmar Ventana LE 3812, this is my first rv, can anyone give me their experience on having a stationary system as oppose to an in motion system?

spinn · 02-10-2015, 09:34 AM

Quote:

Originally Posted by USCGIS

I'm in the process of ordering a Newmar Ventana LE 3812, this is my first rv, can anyone give me their experience on having a stationary system as oppose to an in motion system?

Welcome and congratulations USCGIS! We were discussing air compressors are you asking about satellite antennas?

Steve

USCGIS · 02-10-2015, 08:22 PM

Yes I was, can you please tell me where I should post my question?

spinn · 02-11-2015, 12:30 AM

Perhaps one of our good moderators will move USCGIS post to the technology forum. Or you can start a new thread there or her in the Newmar forum.
I am sure you will get best advice in either.

Enjoy your new coach