Computer crashed… sorry if this isn’t as comprehensive as you would like…
I can only speculate on the effects of motor oil on tires. Well, first off, there’s a risk of greasing your tires up… accident?
Anyways, I can only assume the tires will look nice for a bit. After that, the greasiness will only begin to attract dust and dirt. Longevity?-- no clue.
I guess it’s properties are akin to that of Peanut Butter on plastic trim. While it looks spectacular, the durability leaves something to be desired, and while looking good, it relies primarily on the oils to keep the trim looking good. With that, the oils attract a ridiculous amounts of dirt and dust. In that case (trim) dying is the only way to go on severely neglected trim.
Hope this deters you from trying motor oil on your tires!