Here is a great link I found and used while my X535d worked. It is currently in the shop for an exploded Urea tube.

I did do my reaserch and according to the teamsters in transportation I spoke with. all diesel is the same. It was mandated by law that they make and use low sulfer Diesel Kind of like when they got rid of leaded fuel. ALSO I GOT ABOUT 28MPG. AT THESE GAS STATIONS!!!

www.gasbuddy.com

it's free and dose Diesel also