Neritch Report post Posted February 9, 2015 Ultra low sulfur fuel (required for diesels using DEF) is generally not available in Mexico. We have been thinking of joining a Baja Peninsula caravan but don't want to damage our RV's engine or emission system. Caravan companies claim that using non-ULS fuel in Mexico will not permanently damage the system. I have not been able to find anything from Cummins or Freightliner (our chassis manufacturer) on this subject. Has anyone seen documentation on this from an engine or chassis manufacturer or other authoritative source? Share this post Link to post Share on other sites
wolfe10 Report post Posted February 9, 2015 Nerith, Welcome to the FMCA Forum. A little more research may be in order. It is my understanding that fuel on the Baja, particularly northern Baja is actually imported from the U.S. and is ULSD. No so on the mainland. Again, you need to verify, but that is my understanding. Share this post Link to post Share on other sites