I just put in 400ml to top mine up and it has done 6,500km (4,000m) since the last oil change. I use a semi synthetic 10-40. Odometer is 41,000km and I have the oil changed every 10,000km.
My mechanic advised that in his experience, BMW N-series engines are known to use oil and that it is nothing to be concerned about. In his opinion, there is not appreciable benefit in using full synthetic oil in the N-52 as they will just use more of it!
I had a lengthy conversation with the mechanic that did the pre-purchase inspection my car, around modern oils, engines and service intervals. He managed the BMW dealership garage in Auckland for 20 years before going independent. His opinion was that thin, synthetic oils where not good for modern engines regardless of what the manufacturer stated. He said their motivations were not always based on what was best of the engine, but rather what legislation/ regulation they needed to meet around emissions and fuel consumption as well as buyer perceptions i.e. longer service intervals meant cars must be better. He said there was increasing examples in modern, (mainly European cars) where engines were having catastrophic failures that had followed the manufactures service intervals.
Although not a performance car, he noted that the NZ fleet of St Johns ambulances were having serious issues with engine life, (Mercedes Sprinters) and all were using thin oil recommended by Mercedes. He said they were having engines fail/ wear out at 200-300 thousand km. They changed back to a heavier full mineral oil and now the engines are lasting in excess of 500 thousand km. Fully appreciate they are diesel engines, but very interesting, nevertheless.
North West Surrey
