Originally Posted By: Nissan101
What if my car recommends 20w50 for my temperature or should i put a 0w20 no matter what.....-_-
No, if you live in a very warm area and your manufacurer recommends 20W50 you should stick with thick oils.
Please do not take OP's post as anything conclusive. He has coolant in the engine oil which he used some sort of quick fix on, then had slightly elevated levels of Ni and Fe on one run of M1 0W40. It is clear OP is biased towards thinner oils being better, and his analysis of his data reflects that.
Theoretically both oils should protect sufficiently from wear under normal operating conditions. The problem is your operating condition is high temperature, and while a modern 0W20 is probably thick enough to leave a functional lubricating film even in your conditions, why risk it?
From
"THE ESTIMATION OF LUBRICITY AND VISCOSITY OF ENGINE OILS", which compares wear between different oil weights and syn/semi/dino:
Quote:
All the tested mineral oils, semisynthetic and
synthetic ones are characterized by the similar
resistance to wear. Only Shell Helix Super
15W-40 SJ/CF stands out as it shows the worst
resistance to wear and the highest resistance to
motion.
The progress that took place in the new
generation of engine oils on semisynthetic and
synthetic bases counteracts excessive wear of
elements at variable conditions of work and
simultaneously decreases the resistance to
motion in the whole range of operation.