WalMart Oil filters are made my Champion Labs (not the same ppl that make Champion Spark plugs).

Champion also makes the Oil Filters for STP, ACDelco, Bosch, Mobil 1 and K&N.

As far as Supertech oil, I doubt that it was causing your issues. Supertech oil, like all other oil you can buy at wal mart or your FLAPS, has to carry the API Diesel Rating of CI4. I dont see how this oil could cause your problems.

Did you save some of the old oil to send to Blackstone Labs for analysis to see what the real issue is?

As for me, I don't think I would use Supertech in my SDL, just because it only costs a little more to run a better oil. In my case, I use Royal Purple and send a sample into Blackstone every 3000 miles.

Just my .02, but if you're really concerned about the oil, maybe a good place to get more feedback is bobistheoilguy.....

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91 350SD
14 F150 Eco
19 Fusion Hybrid
11 GT500