My 2012 Porsche Cayenne 3L Petrol requires complete gearbox / transmission oil change at 85,000kms ( some 53,000 miles ). Is this reasonable / to spec - In South Africa this translated to some R5,500 for oil , R3,000 for gearbox filter and R2,600 for sump gasket : Total some R10,000 just for oil / parts !