TT fuels aren't necessarily the "best". TT simply assures a good minimum standard is met. If a fuel is not TT certified, it could be because it's crap, or it could be because the company doesn't see the ROI in the license efforts and costs.
I see this no different than API licenses/certs; those assure a minimum which is "good enough" for most applications. There are companies which can easily surpass those standards, but for me to purchase their products, they have to PROVE it to me. When I use HPL, it's because I trust them to provide a product which exceeds the API standards because I've personally seen the testing/validation proof. I've spoken with them in their lab and seen their production facility. Though I've not had such an opportunity with Amsoil, I would also trust them fully.
Point being, don't "tell" me you're better ...
prove to me you're better. Bring the receipts!
I've read the BP marketing info. I do believe BP (and subsidiaries) to be a decent product line and I don't think they're purposely lying. I just want to see the DATA (the tests run and subsequent results) which prove their claims. It's not that I doubt their claims; it's that I want to verify their claims. As of yet, I've not seen anything but marketing claims. Where's the PROOF? I that they reference ASTM D6201, but they don't tell us their results and how those compare/contrast to TT standards. I want to see what tests are run, so I can research the test and understand what it does and does not assure. Then show me the results of your tests relative to those standards.
Here is a quote from their FAQs ...
"...
in engine test stands incorporating ASTM, industry standard and new, cutting-edge test procedures."
They only reference one ASTM standard, and say nothing as to what the "
industry standard and new, cutting-edge procedures" actually are.
NOTE: ASTM D6201 concerns intake valve deposits.
https://store.astm.org/d6201-19a.html
That does not address fuel injector cleaning, and other things which fuel can do if properly formulated.