My question is for anyone familiar with the newer Nissan direct injected VQ35DD engine, like found in ~2017+ Maximas, Pathfinders and Muranos. Do you notice what seems like these engines blacken the engine oil very quickly? Like within 1-2K miles? I've got about 2900mi on my most recent oil change and judging from how the oil looks on the dipstick, it to me looks like you're checking the stick on an old diesel engine the oil is so black! I know color means nothing, but I know the non-direct injected VQ35DE in our 2016 Quest didn't blacken the oil badly at all between the ~5000mi OCs I did on it. I found this to be the case shortly after we took ownership of our 2019 PF SV model with ~24K miles on it back in Oct 2019. It was an ex-rental. The vehicle was taken in by the local Toyota dealership and they had changed the oil just before I bought it. After a few weeks I noticed the oil looked disturbingly black and not really trusting the dealer oil change, I changed it myself in the beginning of November. The Toyota dealer had used a cheap Napa Pro Select filter and unknown oil. I changed it with a Nissan filter and Napa full synthetic 5w30. Nissan recommends 0w20 for all later model VQ35 engines. In the case of our 2016 Quest with the older VQ35DE, the OM also recommended 0w20, but said you can use 5w30 for severe service. This is why I'd prefer to stick with 5w30 for the new PF as well. Could it be DI fuel dilution? The engine looks spotless from what you can see under the oil fill cap. It runs silky smooth and is averaging ~19mpg day/day and much better on straight highway travel. I fear going beyond an old school 3K mile oil change interval on this.