HTHS testing? 🤔

Joined
Jul 31, 2025
Messages
200
Location
CO
Aside from the manufacturer pages and documents, what is the method that the average Joe could use to get the HTHS of an oil?

We don't have access to multimillion dollar equipment obviously… But is there an oil testing lab that anyone knows about that could do it?
 
If the oil specs aren't listed by the manufacturer, you can most of time get the HTHS viscosity if you contact them.

What oil is it?
 
I have difficulty in getting overly interested in what would be minor variations based upon what is a minimum HT/HS dictated by an approval. I know that VW 504 00 requires a minimum 3.5, so that's what I go with. If I was greatly concerned that it wasn't sufficient I'd go with a 50-grade oil. Or purchase a brand that does provide the information. I'm not too brand centric in light of what an approval provides.

You've advocated for Amsoil in the past, don't they provide this information?
 
New oil sample or used oil sample???

Maybe I'm "painting with a broad brush", but don't the "better" oils provide this in their PDS? I know HPL does, Their PDS clearly lists the High Temp High Shear Visc, cP, according to the ASTM D5481 test standards. I'll bet Amsoil, RedLine, etc., also do?

Ed
 
One could request a quote here (no published price list it seems):
https://www.savantlab.com/wp-content/uploads/2023/05/Savant-Labs-Test-List-by-Category.pdf
https://www.savantlab.com/viscosity-testing-and-shear-stability-testing/

In the TDS one could see only the fresh oil value (if published at all) , and since

HTHS viscosity are measured with methods
such as ASTM D4683 (Tapered Bearing Simulator), D4741/CEC
L-36-90 (Tapered Plug Viscometer), D5481 (Multicell Capillary
Viscometer) or with an ultrahigh shear rate viscometer (USV)
...they probably produce slightly different results.

https://koehlerinstrument.com/wp-co...-Multi-Grade-Polymer-Thickened-Lubricants.pdf
 
Thanks to all.

Not talking about used oil here.

Looking at Harvest King 5w40 all fleet synthetic at Big R.

From what I read online, the manufacturer is different depending on the region. We're in Colorado; haven't put my hands on a bottle in person yet, just been poking around online.

Appreciate the machine references...interesting but not a wise purchase for a one-off test.
 
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