I've worked on a truck (07 6.7) that the customer has choosen to run some sort of bio in. Obviously veg oil based from the smell. The bio gets in the engine oil through the process of regen and mixes with the crankcase oil which turn the old soot suspended in the crankcase to black tar. Plugged the oil filter up and set low oil psi codes as well as complaints of "oil psi gauge drops to zero" from the customer. Ruining his turbo is how I found the tar issue. No warranty. He's also had check engine lights throughout this adventure pertaining to NAC, DOC, DPF issues.