To be fair, I've been told that Quaker State oil formally used a high paraffin wax oil base, when it was refined from PA crude; on the one hand it did leave deposits in engines, but conversly, paraffin oils were a good lubricants in an automobile engine. I heard this complaint of sludging several times as a part-time oil changer for a shop that used QS, and was told that once QS improved their additives package (which I assume also to be transformation to a groupII from a groupI). In any case, QS is no longer in the Quaker State and is based in Texas, as is Pennzoil, and that they are now both a part of Shell Oil...quote:
Originally posted by labman:
After Ashland Chemical fired me in 1975, I switched to Pennzoil. In the late 80's, I cut corners and used QS. After finding a sludge problem, I went back to Pennzoil, and haven't used anything else since. I am not about to go to whatever Wal-Mart has cheap.
Really thinking of abandoning dino for Platinium.