Here is a teardown of Hyundai OEM and Purolator filters side by side:
http://www.hyundai-forums.com/222-yf-2011-sonata-i45/130394-dissection-oem-hyundai-filter.html
The OEM filter certainly appears to be of very high quality and is not very expensive - my local dealer has them for $7.00 or they...
