Did a sample of a 8.3 cummins in a Magnum farm tractor with 3,000 hours Lead came back Critical at 156 copper was 1 and tin was also a 1 we use Cenpeco 15-40 in it with a cup of Justice Bros heavy duty lube additive cut filter open and found nothing what is the deal with the lead being so high sample was not contaminated at all. If bearings were wearing that bad shouldnt tin also be very high? the oil had 100 hours on it when changed does that additive have lead in it.