I started reading the article by Dr Haas in the Motor Oil University section, not yet finished. In describing the formulation difference of mineral multigrade oil and synthetic multigrade oil, he stated that mineral 10W-30 (example of multi-grade) uses straight 10 oil and then VII to make it thicker to meet 100C viscosity, while as synthetic 10W-30 oil uses straight 30 oil and no VII's. Is this correct? Then how does synthetic 10W-30 meet 10W requirement? Excerpt as follows:
Quote:
A 10W-30 multi-grade mineral based oil is made from a 10 grade oil and has VI improvers added to thicken the product in a 212°F engine. It acts as a 30 grade oil when hot. It acts more as a 10 grade oil at startup. I remind you that a 10, 5 or 2 grade oil is still too thick to provide lubrication at startup. They are all too thick at startup. There is currently no engine oil thin enough to operate correctly at startup. They all cause excessive wear at startup. Again, we are discussing the needs of my single hypothetical engine for around town driving.
Oil Type Thickness at 75° F Thickness at 212° F
Straight 30 250 10
10W-30 100 10
0W-30 40 10
Straight 10 30 6
Straight 5 20 4
Straight 2 15 3
Straight 0 12 3 ( est )
( Oil Types – Synthetic / Straight varying Thickness )
Let’s look at the make up of synthetic based oils. A 10W-30 synthetic oil is based on a 30 grade oil. This is unlike the counterpart mineral oil based on a 10 grade oil. There is no VI improver needed. The oil is already correct for the normal operating temperature of 212°F. It has a thickness of 10 while you drive to work. It will never thin yet has the same long term problem as the mineral based oil. They both thicken with extended age.
Quote:
A 10W-30 multi-grade mineral based oil is made from a 10 grade oil and has VI improvers added to thicken the product in a 212°F engine. It acts as a 30 grade oil when hot. It acts more as a 10 grade oil at startup. I remind you that a 10, 5 or 2 grade oil is still too thick to provide lubrication at startup. They are all too thick at startup. There is currently no engine oil thin enough to operate correctly at startup. They all cause excessive wear at startup. Again, we are discussing the needs of my single hypothetical engine for around town driving.
Oil Type Thickness at 75° F Thickness at 212° F
Straight 30 250 10
10W-30 100 10
0W-30 40 10
Straight 10 30 6
Straight 5 20 4
Straight 2 15 3
Straight 0 12 3 ( est )
( Oil Types – Synthetic / Straight varying Thickness )
Let’s look at the make up of synthetic based oils. A 10W-30 synthetic oil is based on a 30 grade oil. This is unlike the counterpart mineral oil based on a 10 grade oil. There is no VI improver needed. The oil is already correct for the normal operating temperature of 212°F. It has a thickness of 10 while you drive to work. It will never thin yet has the same long term problem as the mineral based oil. They both thicken with extended age.
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