Originally Posted By: waltywalt
What 5w30 syn oil has the best noack numbers and doesn't shear down so much.
Are you willing to go to boutique oils, or want to stick with readily available synthetics?
AMSoil HDD has 9% NOACK, and is very shear resistant. It's a diesel oil formulated for pre-2007 engines, so it's probably high SAPS.
RedLine 5w30 has 6% NOACK, and is very shear resistant. It is formulated for gasoline engines.