Bill, I have owned four new Porsches, '11 Cayman S, '15 Cayman, '16 Macan S (wife's), and now a '17 Cayman 718S. I always change my own oil, filters, rotate tires, etc. Just keep your receipts, showing the kind of oil and filters, etc. I even did my own recall, when a Clutch Switch on the '15 was on recall--didn't have time to take it to the dealership, so I bought the part online ($45) and installed it myself. So I don't know what the dealers charge for services, since I do it myself, when I can.