Quote:
Originally Posted by RobertISaar
i too am an active BITOG'er and would like for everybody to get the best of what their money is paying for. 10 and 15W oils are old-school thinking, there's no reason any engine running a 30, 40 or 50 weight oil can't run 0W-30/40/50, or at least 5W-30/40/50.
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From what I understand from scouring the BITOG site (mind you, not too vigorously, as it bores me a bit), 5W40 oil starts off as a 5W oil and then stuff is added to get the 40W when hot. As oil ages and starts shearing, this additive stops doing its job and oil gets thinner and thinner when hot.
I could be wrong.
With this understanding (or lack thereof) I always wonder after how many miles does shearing start to have a significant effect - within the recommended oil change interval? If so, that's not good, and a reason I would shy away from lower weight oils.