I used Castrol synthetic when it first came out, in a slant-six Duster. It made the temp gauge run noticeably lower in the summer, but I switched back to regular oil as leaks got worse. I don't think the oil caused the leaks--it leaked as much with regular oil.
I don't use synthetic in my Pontiac. It has a Crane Cam, and I asked one of their tech operators about synthetics in the early '90s. He said they don't recommend them because they've seen accelerated wear over conventional oils. That doesn't fit with most of what I've heard about synthetics. The cam instructions recommend PA crude oils, so maybe Crane owns some oil rigs.
|