Castrol synthetic or Valvoline?

stixx said

They have run tests with simple standard motor oils and let it in the engine for, say, 50000 miles. They just topped it off when required. After that they drained it (being pitch black then) and had it analyzed. It was still oil and was still doing its job, it had degraded but not that it would have hurt the engine.

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That reminds me of a story. I had a buddy in the Navy, Guidry, who had a '73 Pinto. I asked him one day what oil he used in it at oil changes, and he got a look on his face like he had been hit by lightning......"You mean you're supposed to change it?" he said with his Cajun accent.... I changed it for him then at there, with 30 k miles on it; it was like molasses. I would not like to have had that engine.....