My general recommendation is at least every 12 months or every 10,000 miles, whichever comes first, and I try to change oil and filter every 5000 - 7000 miles at our local lube station. If yours is a Disco Sport with the Ingenium diesel engine, and you drive relatively short distances, then you might need to change engine oil and filter more frequently. What is crucial is to open the door before you switch off the engine. If you smell 'heat' from under the car DO NOT SWITCH OFF THE ENGINE because the DPF is actively regenerating. Drive it another 5 - 10 miles, otherwise the system will dump neat diesel into your engine oil, contaminating it. More here: www.honestjohn.co.uk/carbycar/land-rover/discovery...d /