Penz oil
Any place that sells Motorcraft oil filters will have an application chart showing you which one fits your Focus.
WIX makes all of NAPA's oil filters
Champion Filters (not connected with Champion Spark Plugs)
Ashland makes the oil to Kubota spec
Champion
Purolator
hastings
I work at a carquest auto parts store and believe that kendall makes motorcraft oil. The bottles are exactly the same, only different colors. Ive also seen on the internet that kendall makes it.
You do not have to use OEM filters. You should however use a quality filter. Purolator, Wix, Bosch, AC/Delco, Motorcraft, Mopar, and all OEM filters are quality filters. Avoid cheap no name filters.
I have been searching on the net and found out that WIX makes the carquest oil filters. If you look at the carquest oil filter box it will say Wix Filtration.
Purolator, Wix, Bosch, AC/Delco, Motorcraft, NAPA, & Carquest, are all excellent filters.