broncobowsher
Contributor
Or they have a crap compressor that needs extra filtering.Grade E is a garbage standard. I can get that with my bicycle pump.
Now then-Most compressors can reach the "OCA" standard with normal filtering. I have 2 compressors (Bauer 9cfm-ish) that always meet the OCA standard without extra filters. Those that say that Hyperfiltering is necessary to reach "OCA" is just hypermarketing.