Description:However, it seems some diesel engines are now using catalytic converters, so we are becoming reluctant to recommend diesel oil, but at this point we have no alternative. We, as cam suppliers, and our customers are faced with decisions about oil. One of the problems we have is finding out what is in the oils we use and need. We are not talking about some zippy advertising cute name. We need to know exactly what additives are being used and in what quantities.