According to the link above AC Delco is made by Champion Labs in the last decade, same company as KN&N and Mobil 1 (KN and Mobil1 are identical except for the nut IIRC).
Napa and Wix are identical as well.
According to the link above AC Delco is made by Champion Labs in the last decade, same company as KN&N and Mobil 1 (KN and Mobil1 are identical except for the nut IIRC).
Napa and Wix are identical as well.