Sienna Dude, while I don’t think anyone wants to see that kind of fuel dilution, I think you really need to step back and focus less on the supposed problem of dilution and more on what you know to be true:You raised a great point about the durability of these engines. Toyota and Honda must have considered fuel while designing these motors. Maybe I shouldn't worry and just keep going. I have made it to 200k, the engine runs perfectly fine.
- Your van has made it to 200k with no real issues. The consumption is well in check, the engine is performing quite well
- The wear indicators in UOA are showing very low wear.
In other words, if the fuel dilution was an actual problem, you would have seen something in 200k miles other than high fuel on your UOA. TBQH, if you weren’t running UOA, would you think for a moment there was any problem?
The low temps are a feature, not a bug in many ways. Yes they make it harder to burn off fuel dilution. But those same low temps also assure that:
- Your oil oxidation rate is super low
- Your viscosity is much higher in the running engine than the KV100 would indicate.
- The low temps slow some of the chemical reactions that make fuel dilution such an issue. (I.e. carboning).
YOU DO NOT HAVE A LOW VISCOSITY PROBLEM.
Keep doing exactly what your doing and don’t sweat the non-issue of fuel dilution. your viscosity in actual engine running conditions is far above what the KV100 would suggest. Heck, you might be able to tolerate 10% or more dilution!
Dilution in and of itself is not a problem. Unchecked, it can certainly cause problems because fuel is a contaminant. But that’s why we change oil.
Given your steady usage with consistent temps, honestly you could probably make a mineral or blend 0w20 work on shorter ODIs quite cost-effectively, changing the filter every other time.
You are an attentive and conscientious owner and could use about any oil successfully. You’ve done well to get you this far, don’t question what’s worked for 200k.