Rural king (farmers fleet) motor oil.

S'cuder said
Because it's doubtful it will help any, and possible it can cause harm.
If you do have a failure, no oil company will honor a warranty on an oil that's had additive introduced to their solution.

Maybe so idk. But I am seriously doubtful that Lucas oil would make and sell millions of bottles of this stuff if its gonna cause damage to a engine. Even so there isnt an oil company out there that's gonna warranty a 20 year old truck with 289k miles