I became an
Amsoil Preferential customer but didnt take it any further, I reckon they are full of s**t, as they always claim no other
oil is close, and they have the lease on cutting edge technology, and everything they do is better!
At this stage I am considering Motul 15-50 race
oil, which is like Castrol RS, can be used on road and race cars, Motul is purely
synthetic made out of something like coconut
oil, and serious race cars use it, I dont think
Amsoil is widely used in the International race scene like the Motul or Castrol synthetics. Some Castrol synthetics are not pure synthetics and normally oil companies list them as such!
STG,
In 1972 Motul was the first to use Ester oils in Motorsports, transfering the technology from the aeronautics industry. Motul 300V versus Competition, Castrol RS 10W-60, Mobil 1 15W-50, Red Line 15W-50, Total Activa 10W-50
exceeded all these oils, in most areas of these tests, Friction Cameron Plint, NTHS, Shear stability, and Wear Cameron Plint, Oxidation Stability, the only oils that bettered it at NOACK Volatility were Castrol RS, Total Activa, plus Mobil 1 and Red Line were close to Motul 300V on the Friction Cameron Plint test. Another point with Motul is a reasonably high content of
Zinc and Phospherous, which may benefit the engines used in most Cobras. I guess we all have choices and are biased after we have made our decision on which oil to use. One down side with Motul is I think it may be a lot dearer than the oils you have quoted, but you pay for quality!!!!