Does a higher compression engine benefit more from an oil that has a higher HT/HS (high temperature/high shear) rating, vs. a lower compression engine? Street engines, not racers.
Does the higher compression cause more of a shearing effect on the oil?
I don't exactly know about shearing itself, but higher compression engines put more stress on the rod bearings, and have higher combustion chamber temps for the most part. I would expect these two features to put more stress on an oil and engine, thus I would prefer an oil with higher capabilities in those departments to improve cooling and have stronger viscosity in the bearings.
My engine is 11.5-1 and I'm using Castrol 5w30 for the first few thousand break-in miles. I will post the oil analysis after I change the oil for the 2nd time. Then I am going to switch to synthetic for 2 oil changes, sampling the 2nd change to determine which oil shows better results.
Should be interesting...
Edit for typo
[ January 16, 2003, 01:31 PM: Message edited by: DABEAR95 ]