Reason I Only Use Hyundai OEM Air Filters Now !

montreal ,canada
Well, Not sure what to tell you. I have used aftermarket filters on my wifes Sonata for 9 yrs. 2012 Sonata GLS we bought new in July 2011. I changed the oil every 5k miles with Castrol Edge EP 5/20 using whatever air filters were on sale at Rock Auto and used the "Premium Guard" oil filters also through Rock Auto. Had UOA's done with zero issues. You may want to check your air intake hose clamps. Maybe they are lose? Or maybe your TB clamps are lose. Dirty air is getting in somewhere, but I doubt its because of aftermarket filters. Just my 10 cents. Over 9 yeas and 100k plus miles on our Sonata.
Odds are much more likely that you'll get a better fit with OEM. Seriously, swapping out Castrol Edge EP at 5k intervals? Be better off using a blend instead of wasting money and a top quality engine oil.
Caldwell Idaho
I noticed a tighter fit with the Toyota OEM air filter for my 1992 Pickup. It's a shame I just bought a couple of Wix filters for the Toyota and Subaru. I am reluctant to use them now..
That is the round filter? I had a 92 Toyota p/u with the 3.0 engine one of my most favorite vehicles ever I used rtv to glue the air filter to the clean side of the housing.