Originally Posted By: glennc
I never thought to question the HTHS of this oil but would probably rule it out based on this. IMO >2.9 probably means 2.9 or slightly more, such that with the margin of blending variability any given batch will not fall below that number. So you might see 2.95 or even 3.02 but probably not 3.1. That would be my assumption until I learned otherwise, anyway.
Glenn, if you are truly interested in challenging your assumption then I'd suggest that you contact Bill Garmier of RLI directly. I'm sure he would be more than willing to clarify the meaning of HTHS > 2.9. My guess is that the oil is greater than 2.9 by design, and that it is not tested.
This number was the same specified for the 5W40 oil for the Audi RS4, which "requires" an HTHS of 3.5. I can guarantee you that that RLI 5W40 Biosyn had no problem holding up to 12 total hours of track time, across several days at full engine power and maximum rpm, all within one 10K OCI, and showing no indication of increased wear(as sampled at 3500, 6500 and 9500 miles during the OCI, on an engine with 25 to 35K miles)