Quote:
Originally Posted by glamcem
two things I am trying to understand:
Why do you say that NA guys don't need higher oil pressures say for instance at 270F degrees? Since both NA or FI suffer from the same oil pressure issue at the given temp regardless of the power levels.
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Hydrodynamic wedge, that's why. Just like in the hydroplaning tire analogy from the other thread, we have a LOT more weight pushing down on the tire that's trying to hydroplane making harder for it to form a "wedge" of water in front of it allowing it to hydroplane (aka for lubrication to happen).
A stock FA20 (200hp) and a FI-FA20(400hp) elicit very different cylinder pressures and forces upon the oil, however their con-rod and crank journals
stayed the same. So one needs to take into account the right oil viscosity needed to maintain that hydrodynamic wedge in the bearings that's needed to support the extra power of Forced Induction
or the extra thinning (viscosity loss) from extra heat
or both.
Quote:
Originally Posted by glamcem
What makes you think that those brands stay better? Mobil 1 5w-30 provides equal or better viscosity grades than those brands you mentioned at 1/4 of the cost  |
UOAs. Mobil 1 US blends seems to be pretty standard affair while their 0w40 Euro-spec blend is much better because it's meeting a higher standard (and the UOAs are solid). From my own nerding-out on VOA/UOAs, the Mobil 1 0w40 is the only OTS Mobil product I'd consider (that's not racing specific) and if you're dead set on 5w-30 then you are better off with the 300v.