Also, in the early 70's there was an actual problem with seals that were designed to absorb a bit of something from the oil, which caused them to remain at their specified thickness. The early synth oils did not have this stuff, and consequently, the seals shrank and would start leaking. This problem was quickly remedied by adding whatever-it-was to the synth oil. Problem solved by 1975, but the myth lives on almost 30 years later.
I switched to Mobil 1 at about 50k on my 96 with no problems or regrets.
