I read some where on the net that Castrol Syntect and Syntec blend are using a new formula that uses a blend of mineral based oils, and there are other brands doing the same thing yet they are still classified as full synthetic.I also read that Mobil1 is still 100% synthetic which other oils beside Redline,Amsoil,Royal Purple are 100% synthetic.

 

I think that only RoyalP's RACING oils are full synthetics, their regular oils are not. I don't know anything about the other brands you listed.

-Max

 

Mobil1 is pure synthetic.

My dad uses it in all of his cars(2vipers, porsche993turbo)

Good stuff

 

Exxon superflow synthetic is 100% synthetic plus its about $1or so cheaper than all other synthetics.Any one using this brand.

 

amsoil is the first and 100% synth. i don't beleive mobil 1 is and i would only use the ones you listed.