So last month I did the third oil change on my 2013 (last gen) Audi A3 TDI. I have followed the Audi service recommendations changing the oil at 5K, 15K and 25K. I always have used the dealer recommended Castrol EDGE Professional LL03 VW 507.00 certified oil that I purchased from the dealer. I figured at 25K that most of the engine break in was done and this would be as good a time as any to check out the oil and see if the VW recommended 10K OCI's are in any way shape or form reasonable. I hoped that it was because this oil is expensive at about $5 per L. Anyways, these results are satisfactory enough to keep on with the 10K OCI, though I'll probably test again at 45K if not 35K. I figured you guys might be interested so here you go.