I have been following the forums concerning centistoke values @100 and how they effect some of the "noisy" hydraulic lifters out there specifically but not limited to the morel lifters. I've seen where Castrol 10w/30 has been recommended due to it being I believe lower than [email protected] 100. I'm trying to understand why this number has importance. I use Amsoil in my vehicles and their signature series oil at 10w-30 grade is 10 @ 100. Can I assume with information I'm hoping to validate here that would be a good choice? Not looking to get murdered or start a huge debate I'm looking for a solid exanatiin I can learn from. Thanks in Advance.