Just for general discussion, I noticed an interesting thing between these. 0w40 has a lower viscosity index than 5w40. It is also a lighter lubricant with HTHS of 3.6 vs 3.8 for the 5w40.
They both meet the same European specs like A40, LL01, 229.5 etc but Castrol push 0w40 as the better lube and it is an extra $10 a jug. Other than the difference between 0w and 5w is there anything more to these 2? Due to the lower VI could it be assumed the 0w40 is a more robust lubricant maybe, more shear stable? Which would you choose?
They both meet the same European specs like A40, LL01, 229.5 etc but Castrol push 0w40 as the better lube and it is an extra $10 a jug. Other than the difference between 0w and 5w is there anything more to these 2? Due to the lower VI could it be assumed the 0w40 is a more robust lubricant maybe, more shear stable? Which would you choose?
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