Would blending 5qts of QS Defy 10w40 with 1qt of M1 0w30 thin it out enough for a high mileage Tacoma 3.4l v6 that calls for 5w30? Perhaps with 1qt of 5w20? Just thinking about using up old stock that I have on hand. Thanks!
Why bother mixing a high calcium, zero magnesium oil like Defy with a low calcium, high magnesium oil like 0w-30? Sort of defeating the purpose of either oil. You end up with a lower calcium, medium magnesium oil that no one makes. The viscosity will work out for you. The add pack is an unknown.
I'd wait until you have some lower 20/30 grade oil in PP/PU/QSUD/Castrol Edge to do such a mix. They're more compatible.