hths oils are usually thicker at the 40cst and 100cst viscosity's is what I see (ASTM-D-5293) , separate of PP,the cold cranking (ccs) is resistance of the starting torque, the lower the number ,the better, per given viscosity per j-300 chart, and the mrv is cold flow at a certain temperature (lower is better) ,usually charted at a neg, cold temp (MRV = TP-1 test ) ,again reflective to the oils viscosity,,,the type of base stock and addition of viscosity index improvers come into play mostly with the PP ,resource conserving (RC) is also reflective on the thinner side of the oils viscosity in order to achieve better lower internal resistance in the engine (MPG) ( friction modifiers & moly are a player) ,and the HTHS number is reduced as a result of this lower viscosity.