Originally Posted By: A_Harman
Why do they say viscosity is in the 10w60 range, when it's barely hanging on to the low end of the 50 range?
I've often wondered that exact same thing! Especially if you check out a variety of Motorcycle UOA's you'll often find variations of the SUS Vis of a 40 grade oil. Here's an example of four UOA's off the first page: 69-76, 65-78, 67-80, 64-76; what's the purpose of having deviating levels if the measurements are meant to remain within a given spectrum (and their range being out of sync with standardized levels)? Are they taking into account fuel dilution and altering the specs based off that or from another variable?