diesel maintenance is same as petrol, after every 5000 Kms, i know this from my sunny 93, it went for 217000 Kms and servicing included oil, oil filters, general checkup. never missed or delayed on any filter or lubricant, never let it overheat, and it gave me all the service i ever needed, i sold it in good running condition in 2003, that person is still running the car on same engine without any extra heavy expenditure.