So some info on air filters. The oem filter definitely lasts 30k at the very least. I used mine for 30k and the performance and fuel economy alhamdulillah remained the exact same. You can just clean the filter by tapping the dirt out if you get too concerned. Our dealers are making a fool out of us, even the manual states 30k Kms, do not change it before. Air filter is also not cheap nowadays either. The whole world is now even up to 50k plus, our air is dirty but not that dirty. It's not like we're living in a desert.
Regarding some others saying to go for cheaper filters, don't. Air filter is more important than oil or oil filter even. A cheap filter will let a lot of dirt in and reduce the life of your engine significantly. Regularly changing it doesn't help either.
What people need to understand is, an air filter technically gets more efficient the longer it's used. The more dirt trapped in the filter equals more filtration for further air. So a bad filter with poor filtration efficiency even if changed regularly would adversely affect your engine.
Oiled air filters also have very poor efficiency when brand new, they literally need some dirt buildup to perform well. So changing the OEM filter regularly is also a bad move, not just financially.
The gm6 air filter is not as much oiled as gm5's, so it doesn't get very dirty very fast like before either.
Also if your air filter is actually clogged, you will definitely feel a huge decrease in performance and fuel efficiency, but your engine won't get damaged though, so no need to worry if the air filter looks a bit dirty and dealers try to convince you to change it.
If you're cheap like me, the easiest hack is, go to the dealer for your regular oil change, ask the mechanic to change your air filter with another used air filter. Most people get their air filter changed at 10k, so those filters are basically brand new. It is against the policy of the dealers so just pay 200-300 to the mechanic and he'll replace yours with that one.