RE: Can you use 10w-30 motor oil for air filter
As above, anything is better than nothing. that being said, go to your local automotive store and buy a bottle of air filter oil for aftermarket automotive air filters. It is a very sticky oil that comes either in a squirt bottle or an aerosol can. K&N, AIRAID, AFE, any brand will work, and for $20 you will get more than you will get more than enough to last the life of the engine.
Motor oil will help, but is not "sticky" like air filter oil. If I were to use anything other than air filter oil, it would be ATF.