Critic - what manufacturers have YOU checked for the conventional 0w-20?
Ramble_
Since marketed "full synthetic" only means group III PERFORMANCE and greater, are you looking for an oil that would cold crank and be a groupII+? I wouldnt think this would be a stable oil compared to a group 3/4/5 syn 0w. The great thing about a 5w-20 it can be made without excessive, unstable, gummy, dirty VII. If you build a 0w-20 in a group II base you will need a fair % ester and polymethacrylate to prevent an early cloud point and then most likely employ a much light(ER) base stock than whould be utilised building a 5w. Then you add the VII again to reach desired KV100. You're back to the terrible 5w30esque conventional, unstable, junk oil construction again. I say avoid a non-syn 0w anything, unless they are just being honest to not advertise a premium conventional base stock product as a "full synthetic".