[cb62fcni]

There's a number of factors. One is the DPF, a cheaper oil will produce more soot as it is inevitably burned off in small quantities and lower the life of your filter. Another is the extended drain interval; the oil must be able to run in various temperature and conditions for 10,000 miles without significant loss of lubrication or deposit buildup. Bottom line: German engines are built to very tight specifications, and although you might be paying a bit more for the oil for them, this is definitely not something I would ever go cheap on.