That's true. I would say that Red Line shears less than others. Red Line Oils, especially those that don't have a 0W winter rating, tend to thicken with heat and stay that way through the OCI. It would be awesome if the HTHS was measured at the end of the OCI.
The highest VI base oils are PAO typically. You can count on one hand how many major blenders use PAO in their products.
It has a HTHS of 3.7, pour point -45 c and a Noack of 6 for 5w-30
Come on, man. You were loving High Performance Lubricants over in another thread. Now you're recommending Redline???? JK, I know both are great products.
Which one of those specs show that it won't exhibit any permanent shear?
Only way an oil could thicken with heat (barring any other operational factors) is if the Noack was high and the light molecules vaporized out of the oil. Red Line oils seem to have pretty low Noack vavues
Shear happens with VII… VII will make pour point higher temp. and HTHS numbers lower and Noack shows the base oil quality. They all say very low VII. IMO…
Yes, shear happens with VIIs ... so if it has any VIIs then it will still eventually experience permanent shear. The claim (not by you) was there was "no shear", meaning no permanent loss of viscosity due to shearing. HTHS won't necessarily become lower from VIIs. HTHS viscosity has a lot to do with the base oil's HTHS to start with.
Oxidation.
Yes ... but isn't oxidation also occurring while an oil is being tested for Noack? Or is the oxidation more of a long term "operational factor" as I mentioned. Oils that oxidize are also more prone to degradation and sludging ... so do RedLine oils (or any others that actually thicken during use) have more likelihood of sludging compared to others if all ran the same OCI?
I think they're still doing it, to some degree. I wouldn't run AMSOIL any longer in an engine than Mobil 1. Let me back up for a second: given their expertise, I trust Mobil 1 more than I trust AMSOIL, period.
Oxidation is more of an operation factor (and normal for all base oils during service) and is often countered or overwhelmed by permanent shear and fuel dilution. Cheap base oils may oxidize and break-down quicker, but I don't think there's any evidence of oils we've seen oxidatively thicken in service (AMSOIL, Redline) produce sludge (which requires moisture) or varnish in the process, which is a more complex process involving breakdown and plating-out of deposits that can no longer be held in suspension.
In Red Line's case, it has more to do with their choice and quantity of esters used in their formulations.
I'd think it would be the PAO that would do it, as POE is more resistant to high temp oxidation (which is why it is used for turbine oils) and PAO makes up the bulk of their base oil blend, unless you've read something on the subject that I haven't?
Group V - high heat resistance, poor cold flow compared to PAO, no competition with the additives, unlike esters.
I'm sorry, I can't say I have. It was just my assumption based on UOAs I've seen and some of our discussions.
K, I expect what we are seeing are the result of the use of heavier PAO bases, minimal use of VII and very shear stable VII. This means that any viscosity loss from shear is going to be minimal, so then the only real driver of viscosity loss is fuel dilution. If you don't have an abundance of that, then, in service, as the base oils oxidize (mostly the PAO) even though it is slight, compared to other, less expensive bases, it ultimately ends up driving up viscosity.
