Horsepower comparisons on air-compressors made for home-hobby use dont't mean much anymore. Sears, C-H and others use a horsepower rating system which doesn't mean much in real use. Their maximum developed horsepower rating is measured by fixing the motor shaft so it can't turn, turning on the power and measuring the peak current draw at start-up. If you look at the current ratings on some of these tools, they couldn't run on a standard household 15 amp circuit if you had anything else on the circuit without blowing the fuse (or breaker).
Best way to compare compressors is by CFM and pressure. That's why an older 2 HP unit will perform as well as some of the 5 or 6 HP units today.
Some of the oil-less units I've seen use an o-ring to seal a piston, relatively easy to rebuild but don't last as long as an oil crankcase unit.
HLW
