A little food for thought on Volkswagen and warranties. With the advent of ULSD, Volkswagen was getting a bunch of high pressure fuel pumps that shelled themselves causing the need for almost a complete replacement of the entire fuel system. In some cases the cost exceeding $7k. Volkswagen did not like this expense and pulled fuel and oil samples on every warranty claim vehicle soon after, they were convinced that the consumer was accidentally putting gasoline into their diesel vehicles. If anything was untoward in this sampling they refused warranty coverage and told the customer tough luck, see you in court. Happened many times over. Just food for thought concerning oil specifications, warranty, dye and tracer chemicals and VW's track record..