Why does everyone consider that low mileage has to be achieved with short trips? It may well be infrequent use! The BMW service schedule based on how you drive and use the car suits most owners and it is your car and your choice. Many disagree with what might appear to be extended, miles between oil changes but I would not risk an oil change outside the dealership whilst in warranty.

When I had the 118D I did an annual oil change using my Pela 6000. Really simple, get engine hot (do about 6 miles) insert probe down dipstick hole and pump to create vacuum. Did not take long but in truth it did not extract 100% of the oil but enough to ensure it was 90% fresh at least.

Naughty me but did not change the filter.

Used BMW LL04 spec oil 0w30 viscosity.

For the record I did about 7500 miles a year for 5 1/2 years and never had a single DPF issue. Commute was 15 miles each way 3 days a week, the rest was shopping and trips to the country to walk the dog plus the annual trip to Whitby for fish and chips.