Carboned Intake Valves

[fantastic]

Unless there’s a more updated TT+ spec than Jan. 2025 that I linked, this is not entirely true. All they’re testing is the injector spray pattern / cleanliness using the GM 2.0 LHU engine. There’s no mention of testing or setting an acceptable spec limit for IVDs.

1. Will TT/TT+ help with injector cleaning? Sure
2. Will TT/TT+ help with controlling IVDs compared to using non TT/TT+ gas? Sure
3. Will TT/TT+ clean up existing IVDs on a GDI engine (related to OP’s question)? Unlikely.
If there’s any testing spec or standard that attests to this, do share so that I can also learn.

Yes, you see what I see. My initial comment to use TT+ fuel for OP was a good call. If they're not using it regularly then it is a tool to utilize.

 

[Rygrego]

My testing with my cars showed it did.

Octane is merely a measure of resistance to preignition. It would have zero interaction with the manifold side of intake valves as it would never be in contact with the valves in a GDI engine. Which is the side of the valves this post is about, not the combustion side.