My 4cyl 2.2L Toyota Camry with 206k is in the process of switching over from 5w-30 conventional oil to full synthetic. Right now I'm running Pennzoil Synthetic blend. I don't know how good its "Active Cleansing Agents" are doing but I'm using it at 1500 mile intervals, the last few hundred miles of which I drain 10 oz then add 10 oz of Marvel Mystery Oil + change the filter just to be safe).
Anyway, soon I'll be running what I feel is the best oil other than Amsoil: Pennzoil Ultra Platinum with PurePlus (the new version stuff). The problem is that I have some conventional oil I want to use up. So, instead of buying the blend next time, I'm planning to mix my remaining Quaker State conventional with the Ultra Platinum I will start buying. I know mixing them is fine, but does the fact that Pennzoil Platinum is made from natural gas affect anything?
Anyway, soon I'll be running what I feel is the best oil other than Amsoil: Pennzoil Ultra Platinum with PurePlus (the new version stuff). The problem is that I have some conventional oil I want to use up. So, instead of buying the blend next time, I'm planning to mix my remaining Quaker State conventional with the Ultra Platinum I will start buying. I know mixing them is fine, but does the fact that Pennzoil Platinum is made from natural gas affect anything?