Since higher RPMs means the S2000 is operating to the far right on the Stribeck curve, your 0w-30 is perfect for this engine. 6 month oil changes, don't even count miles, time is better.
So the WHOLE engine is operating "to the far right of the Stribeck curve" because the crankshaft is rotating (briefly) at 9,000 rpm?! Even at 9,000 rpm, the pistons still come to a complete stop twice per stroke and the camshaft is only turning at 4,500 rpm.
The Stribeck curve is a theoretical model to model friction at a given moment under known conditions. At any given moment in a running engine, there are a number of different surfaces being put under different conditions and so the whole engine is all over the Stribeck curve at the same time. It can not be used as an oil selection tool.
It can and should be used as an oil selection tool. Engineers do it all the time. Its not theoretical
, as the friction is actual engine run measurements, or whatever physical cam/lobe interface device you might have for it. Corresponds with oil film thickness, which, again, isn't theoretical but REAL. I do agree with your statements about some parts of the engine are always on the left side of the Stribeck no matter what, like wrist (gudgeon) pins at times, TDC & BDC cylinder walls and rings, sure. Understand thats in all engines all the time, so no news there
. It goes without saying.
Like Shannow pointed out, it does make sense to consider the inertia loading. Thats a valid discussion. Hard to say how the torque (combustion) part of journal bearing loads compares to the inertia loads, but in high rpm engines, it could be way up there.