in my area a few years ago, there was a difference in the sulfer amount. the on road was transisitioning to low sulfer but the off road was keeping its higher sulfer content. (15 ppm compared to 500ppm) since then the two types have met together and are now both ultra low sulfer. the only difference is the dye in the off road and the tax savings. i ran the off road back when it had the higher sulfer and i still run the off road now with the lower sulfer in my kubota engines= no trouble yet (over 900 and 500 hours). i do use the power service additive most of the time, especially winter. it has the slick diesel in it to help with lubricisity which the sulfer actually use to do. some older diesels might have issues with the ultra low sulfer with out an additive. i think your bx will be fine on off road. that is what i would use.