Can you elaborate on this?
No, I don't have the time or inclination to do so.
So, here it is briefly: every time I consider them for use I stumble on a surprising lack of concrete data, test results, not to mention the complete lack of engine and powertrain tests and teardowns. The UOAs I find are inconsistent and show inconsistencies with large deltas amongst the same products. Other than forum anecdotes and some spotty marketing, there is a surprising lack of concrete lack of information about Red Line Oil. In addition to that, they are being very secretive, and their latest efforts to overhaul their High-Performance engine oils have failed so far with the most bizarre additive and NOACK values I have ever seen thus far:
https://www.redlineoil.com/Content/files/RLO_CATALOG_2021.pdf
And that was the product catalog for last year. Not confidence-inspiring, not to mention that some of the numbers are out of whack.
Most of everything they make is PAO+POE - higher density lubricants that have poor cold flow. They say they are meant for heat resistance, however, oxidative thickening happens with their motor oils no matter what. The longer you run it, the thicker it gets. It's .... bizarre.
The gear oils have unusually high amounts of phosphorus in them, and the UOAs I found thus far don't show anything spectacular about Red Line's gear lubes when compared to Mobil 1 or Valvoline, let alone AMSOIL.
Their transmission fluids, according to forum anecdotes, specifically the D6, are too slippery. There are some accounts of ZF 8HP transmissions slipping on this stuff. The solution is even more bizarre: just mix in some racing ATF.
Look around long enough and you'll find more of the same.
I briefly considered them for use in my new Durango and quickly abandoned the idea. They have a certain "cool factor" associated with them. To me, that's not reason enough to use their products.
I think this is long enough, I really don't have the time to go into more detail.