But this one is different.

I am about to do an oil change on my black ridge 2.5hp direct drive air compressor. I had 2 options. Gulf western, or penrite. There doesn't appear to be any difference in viscosity, just price. Being the fanboy that I am, I picked up the penrite.

Does it matter? Did I make the right choice? What do you use?

Oil level on one of those is much more important than the brand of oil in it. Keep an eye on that there oil level. lol

Meh I'm not too fussed when it comes to an air compressor.

I just buy the $5 bottle of Gulf western. Works a charm. Mind you, the compressor is lucky to be used once a month.

As Max said - in this case - quantity not quality lol!

Not going to make a real difference if its cheapo gulf western or penrite imho.

I know people that have been using Gulf Western oil in their cars for 150,000km's and it's still running fine as they change their oils every 7,500-10,000km. Mind you, I wouldn't put it my magna but just sayin'

I thought as much. My compressor gets regular workouts with the rattle gun and degreaser gun so I like putting in quality stuff.