We intentionally bought a 2006 diesel GMC (destroyed in 70 car pile up between Orizaba and Puebla. So we bought a 2006 dualie diesel 4x4 Chevie. This is designed for the 500 ppm sulfur diesel. We have a 45 gallon Transfer-Flo which simplifies fuel stops.
Someone near Tulum said a Canadian friend had a 50 gallon supplimentary tank and were fined several thousand dollars worth of pesos for such. Turns out he had been using farming (non-taxed) diesel for his truck and the fuel tanks/fuel lines had that dye that put into farming diesel to catch scofflaws who try to get around not paying road tax on their fuel. You will pay thousands in the US if caught doing this as well.
Reed and Elaine