$50 Site Donor 2021
STP IS really thick.Very interesting! So SN levels of ZDDP (so it isn't boosting that at all) a lot of calcium and holy viscosity batman! 57.7cSt????? To put that into perspective, the upper limit for SAE 60 is 26.1cSt, it's more that DOUBLE that! It is approaching the upper limit for SAE 250 gear lube.