The Smittybilt 2781 12V air compressor is relatively inexpensive and supplies 5.56 cfm at 0 psi. It's fast. We hooked it to a 285/70R17LT Falken WildPeak A/T tire that had been aired down to about 10 psi. Thinking the Smittybilt was like most other 12V compressors, we sat back to wait for the tire to inflate to 35 psi. After a couple of minutes, we checked and were astounded—the tire was at 50 psi! After decreasing its pressure to 35, we proceeded to inflate the other tires, keeping a better eye on what was going on. In only a few minutes, we were headed home on tires inflated to street pressure.
The oil-less 2781 is available for less than $150, making it a great deal when comparing it to other available (serious) 12V compressors. It's not 100 percent duty cycle but will run for 40 minutes before having to rest. The compressor's speed makes needing a 40-minute continuous runtime remote. It has a 30-amp inline fuse for protection and comes with air hose, a gauge, a storage bag, and different hose ends for airing up inflatable mattresses, etc.
The compressor is great, but the hose is cheap plastic. Changing to another hose is difficult as the 2781 has its own hose fittings that nothing fits. We'll be doing some research on how to install an NPT fitting on the 2781. It may be easiest to cut the rubber hose and install a barbed universal quick coupling.
If you need a reliable, powerful 12V air compressor at a reasonable price, check out the Smittybilt 2781.