A friend bought a new CX-9 last year.
The Mazda CX-9 is a very nice vehicle, and it was my other choice if I couldn't make a deal on the Durango I currently have. What I like about the Durango is the engine+transmissiona and AWD layout. It's old school. The CX-9 is more high-tech and has an excellent Turbo Charged engine.
He decided the sample the OEM fill and it had 4.6% fuel dilution at just 211 miles.
That's likely from the vehicle being moved around at the factory, dealer lot, etc. They never warm them up. They turn on, move the vehicle, and turn it back off. Fuel adds up quickly, especially in an engine like that.
He put in High Performance Lubricants PCMO 10W-20 to run for close to 5k miles. The fuel dilution has come way down so hopefully that's clearing up.
The HPL 10W-20 is a high-quality mono-grade that has no VII in it. It can withstand fuel dilution without much of a problem, way better than off-the-shelf oils.
I think running higher octane gasoline would go a long way in decreasing fuel dilution, but that may not be a feasible option.
The 27 abs/cm oxidation is from ester. The TBN, despite 5k miles and 2.9% fuel, is still very strong. Enjoy.
I've seen this repeatedly where labs don't or can't detect esters accurately and confuse the oxygen molecules for oxidation. Red Line is like 90 out of the bottle and stays like that. The TBN, despite the fuel dilution, is truly amazing. I've seen this repeatedly where labs don't or can't detect esters accurately and confuse the oxygen molecules for oxidation.