I plan to change rolls out at 5,000 km (3,000 miles) or maximum of 1 year, not sure of the cost up here for a UOA, but I like the idea of a particle count. I save money on buying less oil, roll change is 600-650 mL (2/3 of a quart) Castrol Edge 5W20, If I send oil samples for testing I am sure...