Originally Posted By: KCJeep
Great find thanks for posting. The general consensus here has always been "Synpower with a weaker add pack". As noted it looks just like VWB with a Grp III syn base stock, except the 0w20 which mimics the hard to find Durablend add pack at least on paper. Very interesting!
Agreed, that does seem to be the consensus but that's not entirely correct. Looking at the test done by pqi on both synpower and napa syn, the additive levels are nearly identical, even the tbn. The only difference I can find between the two is synpower is a little thinner during cold temps than napa suggesting that synpower uses a little group IV and napa is all group III. Just a guess on my part, Ashland does claim to use a certain percentage of group IV in synpower, but they don't say anything about napa syn. reasonable deduction.