Quicksilver,
You should really check your information before you post it. Amsoil is NOT the originator of synthetics. Synthetic lubricants were being developed back in the 1920's. In 1944, the U.S. Air Force used PAG (Polyalkalene Glycol) in aircraft engines operating in Alaska and Canada. In 1971, Motul of France introduced the first all synthetic oil in Europe. If I remember correctly, Mobil developed a synthetic lubricant back in the 60's called Delvac for use in extremely cold climates like Alaska where it was critical for the lubricant to flow at extremely low temperatures. If you read Amsoil's info very carefully, they say, "introduced the first synthetic motor oil with an API (American Petroleum Institute) Service Classification in 1972." First synthetic with an API certification, not first synthetic.
Straight from the AMSOIL website:
"Are AMSOIL Motor Oils compatible with other motor oils?
Yes. AMSOIL Motor Oils are compatible with all other synthetic or petroleum motor oils."
"Is there a recommended procedure for changing to AMSOIL Motor Oils?
There are no special requirements; however, in older vehicles or those with high mileage, it may be advisable to use AMSOIL Engine Flush first. This will ensure that the engine is clean and free of any accumulated contaminants which might have an effect on the service life of AMSOIL Motor Oils. In all cases, it is good judgement to install a new AMSOIL Super Duty Full-Flow Oil Filter (SDF) every time you change oil"
So, straight from the company's mouth, they say their oil is compatible with conventional oil, and flushing is unnecessary except in older engines. 'Nuff said.
