Originally Posted by StevieC
Originally Posted by Brigadier
https://www.bobistheoilguy.com/foru...604432/all/The_Great_Generational_Divide
Quote
"Extended" oil changes on DI are not good. Soot accumulation and fuel dilution rule this out. You say your UOA wear levels are good? Does a UOA measure how soot levels are affecting your timing chain?
Tribologic film, you say? The fuel dilution literally changes your oil. It is not the same oil as when it was new. Fuel dilution(particularly ethanol blended gasoline) reduces(or eliminates) your boundary layer lubrication. It also reduces your viscosity, and essentially your oil becomes a oil/gasoline/ethanol blend. So, if you're saving your tribologic film for your next oil change, forget it. You don't want that one.
There is some evidence that the more used your oil is(as opposed to new or newer oil), that influences LSPI negatively. Thin oil, you say? There is some evidence that lower viscosity affects LSPI negatively. Synthetic oil, you say? There is some evidence for Group I-IV oils, the higher the Group, the more LSPI. These three are all secondary, or tertiary, but still evident.
I didn't mention wear shown on the UOA, I mentioned that the UOA will tell you if the lubricant is good for continued use. You are twisting words and I see you edited this post to include a chart. If you use proper analysis it will tell you whether the lubricant can be used further or it should be dumped. Going by blanket manual recommendations is just a fail-safe and will always be more conservative than necessary because they know the average user isn't going to spend the money to do proper analysis to establish a safe limit.
But that's ok you waste money on more frequent oil changes without confirming what is possible. It will end well for your engine just not for your wallet.
How will an oil be good for continued use if it is full of timing chain destroying GDI soot that is not reported in the UOA? Also, GDI engines produce fuel dilution, enough to potentially remove your precious boundry layer lubrication. Fuel/ethanol are solvents. Not lubricants.
But I am sure Amsoil will have your back.