Like stated above, the car was specd to run 10w30 conventional , im sure shear stability had to do with it, so i wouldnt sweat using a fully synthetic in a 0w30 5w30
ExMachina said: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.
Got to be careful with using "the curve" like that in that the other factor is the load...while the RHS rises with RPM, the loads vary as well.
Originally Posted By: Shannow
Inertial loads on the bearings rise with speed squared.
OK, I see it now, omegasquared x r , yes, where omega is RPM in radians/sec units.
Originally Posted By: Shannow
So a doubling of the speed over a similarly designed engine should double your Stribeck number for constant load, the four fold inertial load increase could reduce your Stribeck number by a factor of 4.
So load = constant, an 8 may be a 16 on the X axis due to speed, the 16 could become 4 when inertial loads come in.
Not quite that simple though, since TotalLoadForce = CombustionForce + InertiaForce, only the Inertia part of that gets a lot bigger. I haven't calculated what percentage consists of the Inertia component, but it may overwhelm the CombustionForce at some high RPM.
Originally Posted By: Shannow
Honda chose a shear stable grade initially in 10W30, and a higher HTHS but potentially more shear prone 5W40 if the 5W is needed, so I think 0W30 is going counter to their thinking on the engine's needs.
If the M1 0w-30 makes one queasy to use, then I like the suggestions above to mix about half-half the stash of 0w-30 with M1 0w-40 or use 100% M1 HighMile 10w-30 good choices all. (The M1 0w-40 is used for some serious endurance racing, so its got what it takes.)