Inexpensive compressor

I run mine for a min before putting load on and yes never shut it off under load, mine is just a cheap yong Heng but has worked flawlessly for 1.5 years, I’m gonna catch hell for this next statement but here is my experience. I’ve never nor will I used “royal purple” I know everyone says use it. But there is no need. I always have used compressor oil from Napa auto, I get it here $9 quart just be sure to change it regularly “if it’s dirty clean it” if you want I will post a pic of the bottle for ya when I get home. Don’t fall for the high priced hyped out “royal purple” stuff
 
I let the compressor warm up before pressurizing it. When I shut it off I open the bleed screw before turning the compressor off. Is this necessary?

it's just done to blow out any moisture left in the compressor, otherwise it would only blow out moisture from the hose, good practice to keep the compressor from rusting and corroding.