TR6oldtimer said:
Brosky said:
If it does, it will not last long. The oil will thin very quickly upon warm up and that will end that illusion.
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Sorry Paul, but actually a 20w-50 engine oil will increase it's viscosity as it heats up. Over time the additive that causes viscosity to increase with temperature will break down and the oil's viscosity at temperature will begin to decrease.
Umm not quite. oil viscosity indexes are related to oil temperature. For a single wt oil it is intuitive that the oil will be thinner as it heats up.
For a multi wt oil, at low temperatures, it will approximately as the lower viscosity # but as it heats us it will act like the higher viscosity# however since viscosity of oil is affected by temperature, the actual viscosity of the oil will be lower at the high temperature, it just won't loose quite as much viscosity as a single wt oil would have.