oliver2000 said:From what I have read, changing back to synth and back to oil MAY make some seals and gaskets leak on a older engine as synth is thinner and cleaner.
wrong, synthetic has cleaning agents that will unclog corners of your block of petroleum sludge that would then make oil leak from said corner
you can change to synthetic at any time, including with 0 miles on the engine
Corvettes, 911 turbos, vipers ALL come factory filled with Mobil 1 (I dont think those engines have bad results
and finally, if you switch back and forth you dont " need to completly drain all the oil from the engine" if that was the case their wouldn't be semi- synthetic - would there?
