Why is my oil black?

[SquareOne]

This is mine at a hair under 7k miles. It’s very bright outside so it may appear to be a slight bit cleaner than it actually is, but all in all I think very acceptable compared to what it once was when the engine was 1st purchased.


Same as Rawze...hyper-miling (best as I can), 3/4 gallon of gear oil, very little idling and strong maintenance regiment. Truck has averaged 8.790mpg over the last 61k miles.