I've got this one as a current owner of the exact same model, engine and year Explorer. Mine is at 298k miles, almost 299k. At 150k it's just purring like it should.
Here's what I do:
Always been syn 5w30 but the brand didn't mater. I ran GC for awhile when it was all the rage, like having your own Rubik's Cube. Before and after typically ran M1 but also Castrol and Penn but M1 was 90% of the time. I changed it at 5k but over the past 5 years or so I bumped it to 7.5k.
My mileage is a little less than when new bc the drivetrain is going, I burn the same 1/2 quart over 5k that it always has and as far as emissions, when the state tests it for re-registration, it's always within spec for a new engine. Bc it's so old, last year the state asked that I bring it in for a random check bc the age is within the suspected gross polluter categoy and once again, it passed with flying colors and even amazed the tech.
The interior of the overhead valves through the fill hole is spotless.
That said, the truck is now a falling apart in most places, except for the engine. Plugs and wires were replaced every 100k, it gets a bottle of Redline in the gas tank before an oil change but that's it.
Engine is fine I suspect for a long time to come but the other parts have seen better days.
Oh, the oil filter was the M1 once they came out and before that, the blue Purolator. The air filter has always been the K&N replacement once it was available. I don't have an iota of faith in the naysayers of K&N because I've run the same filter for nearly 20 years and I find that people who don't like them have little long term use as an owner of one or they just know someone who had one or saw a picture of one that was over oiled.
If I fill the tank to the tippy top and do just highway driving, even with the drivetrain starting to go, I still manage to get 400+ miles per tank.