Eventually Mexico will have to produce ULSD. But when is another thing. The existing refineries are ancient and suffer from a lack of maintenance ( I am not surprised). Pemex does not have the bucks nor is there much political will to do anything. Mexico did sign on about 5 years ago at some International symposium to produce and sell only ULSD. Maybe with the all the changes at Pemex we will see ULSD soon. Not to please Tourists but to prevent pollution in a country that is decades behind when it comes to the environment.
Moisheh