Can HTHS be measured in VOA or UOA?

[TLK]

Are any of the oil analysis companies suchs as this board's sponsors capable of determine HTHS of a virgin or used sample or is the testing procedure too elaborate (and too expensive) for investigating such a casual question as "what are the HTHS numbers for a motor oil whose manufacturer refuses to publish them"?

I've been curious about Royal Purple for some time, because they flatly have refused to publish or divulge their HTHS numbers for any motor oils.

While using similar base stocks to Redline products, I cannot verify that RP multigrade oils meet the ACEA A3 spec suggested for my engine, and thus I have been suspicious. Many friends have asked if it's ok to use in BMW's, but I tell them to shop a different brand since we cannot infer if it is ACEA A3 or not without HTHS.

 

[buster]

No. HT/HS is somewhat related to viscosity, but it's not 100% linear. For instance, most oils that are about 11.3 cSt and greater, have a HT/HS of 3.5. Redline uses alot of Polyolester basestock and I believe that is how they acheive their high HT/HS. A good rule to go by is the ACEA specs. If it meets the ACEA A3 spec, it's at least 3.5. If it's A1/A5, then it's less then the 3.5. Somewhere on this forum are the RP numbers and I'm fairly certain that they do not meet the 3.5 HT/HS for the 30wt viscosities. RP tends to shear actually more then other synthetics.