erik, you have been running the lube in the engine as a addative??? i don't do that but i'm willing to. the dam oil companys keep changing the oil as fast as i can have it tested. do you have the new eos part number?? the gm dealers are brain dead and keep telling me that they don't make it anymore. thats way i have been using stp red it has about 3/4 of the zddp as eos.