I have raised this previously elsewhere and not had a satisfactory conclusion. My 2015 M has a service interval stated in the Thai service book of 6000km where as European manual has it as 12000km - double. This discrepancy is magnified in that on next page of Thai service book where the service is recorded it is 4000km - a third! Going back to the 1970's they used to decrease service intervals of cars exported to hot and dusty countries but this was when oil was much poorer and by dusty it was Africa etc which is not the same as here. I have three fairly cynical theories but any input?