How would you rate the BRP Synthetic? Is it just repackaged Castrol RS 4T Syn? The castrol is MA2.
BRP oil is indeed, repackaged Castrol products (though this can change at any time).
The real debate, which I'm pretty sure will never be resolved, is whether a mineral based oil (Group III) highly modified with additives should be called 'Full Synthetic' just like products using Group IV true synthetic base oil.
The whole thing started in the late 90's when Castol Syntec, Full Synthetic (which used true synthetic, Group IV base oil) switched to a mineral base (Group III) with a lot of additives.
Mobil 1 sued Castrol asserting that since they were no longer using a true synthetic Group IV base oil, they could no longer call it 'Full Synthetic'. But to everyone's surprise, Castrol won the court case (how much do judges know about oil?)
Since mineral oil base (Group III) cost about 1/2 as much as true synthetic Group IV, almost every motor oil manufacturer switched their 'Synthetic' oils to the new standard using Group III mineral base oil with additives. The additives are expensive but are relatively small in volume. Additives also vary in quality and cost. Over all, the end product is much less expensive to produce using Group III base.
Personally I feel it is consumer fraud since the average person has no idea that there are 2 very different standards, both labeled 'Full Synthetic'. But you have to hand it to Castrol, they got the job done where it counts, in court.
Don't get me wrong, Castrol makes a quality product and I personally have used Castrol in my vehicles at times. I blame the court for this identity chrisis. But the facts of this consumer deception, if that's what you want to call it, are not lost to those in the marketing or accounting offices.