Basically, It's a 10.6cfm compressor (@5PSI). The Schrader valve is limiting flow. Similar to if you were to inflate (4) of your kids pool toys and your face turns red. Your face would be LESS red if the pool toys had a 1" inflation valve like many air mattresses.
His words:
MORRFlate-Tyler
"Oh man... thats a huge topic that might be too much to type out... We just recorded an episode about this very thing on Snailtrail 4x4... it should be releasing tomorrow morning. I will try and remember to come back and post a link here... should be episode 451.
in short... it comes down to duty cycle. Compressors can either be "Low Pressure, High Volume" (think of an air mattress compressor... which works more as a special fan than actually compressing air to create pressure), or "high pressure, low volume" which is what all of our off road tire compressors are. ANd the higher the working pressure you need, the lower the volume it can do, due to backpressure pushing back on the compressor cylinders and valves while its compressing air and trying to send it down the line to your reservoir (whether that is a tank or a tire or whatever).
If you look at compressor stats, generally, their advertised CFM is measured at "atmospheric pressure" or zero psi. And, as the compressor gets higher in its working pressure, the CFM will drop. For instance, our TenSix compressors will do 13.5 CFM at zero pretty regularly, but that drops to about 10.6 CFM at 5psi (which is what we advertise at, because very few people are acutally using compressors in the offroad space below 5psi). At 20 psi, we are at about 6.5-7CFM. At 30 psi, we are at about 3.5-4 CFM, at 40 psi, we are at about 2.5-3CFM. and once you get above 100 we are at about 1.5-2cfm. That is because, the higher the working PSI, the more the compressor motor and cylinders have to work to overcome the pressure in your reservoir in order to continue pumping air into it. The harder a compressor works, the hotter it runs. Once a compressor runs too hot, it will either burn up wiring, motors, or gaskets and seals. Any good compressor will have a thermal cutoff switch that measures working temperature and shuts off the power to the compressor before it reaches that melting point (typically around ~200 deg f).
A "duty cycle" refers to a compressors ability to run longer before hitting that critical temperature. So, when you see duty cycles quoted or advertised they should all be based on a time frame. i.e. "50% duty cycle at 30min" which means the compressor should spend 15min off for every 15min it is on and running. In my opinion, the duty cycle of compressors should also be stated within a working PSI range... because the higher the PSI a compressor is working at, the shorter its duty cycle will be due to working harder.
When it comes to 1 tire vs 4 tires and why you want to be careful with some higher output compressors now a days... A tire's valve stem can only accept about 2cfm of airflow at a time. So if you are using a compressor that can output 5.5cfm, 6cfm, or 10cfm, through an orifice designed for 2cfm, you are going to create a big bottleneck of airflow, which causes higher working pressures on the compressor, and lower duty cycles. You can use our compressors to do one single tire, but because that back pressure ends up being so much, the duty cycle dwindles to about 2 min on, 15-20min off. So you dont want to do an entire vehicle doing 1 tire at a time with them."
That said, a lot of folks using these compressors and the numerous brands like it, one tire at at time. You can also add or change to a faster inflation valve, i.e Monster Valve.