Be, Careful of fuel in Mexico. I live close to the border and used to go there for fillups. Fuel is significantly cheaper, figured I was paying 1. 60 - 1. 70 per gallon. Didn't notice any difference in performance, it ran fine. Check with the injector shops in San Diego, advanced diesel performance, omega fuel injection, etc. The shops see the damage it does to fuel system parts. It has a high sulpher and water content. It corroded and pitted the injectors and pump in my 3rd generation. Was told by one of the shops that US fuel has a low sulpher content which can affect lubrication. If you were to fuel up in Mexico recommend you mix with the US low sulpher fuel, add more filters, water separator and an additive to the tank.
03 3500 dually, SLT Laramie, HO, 6spd, Quad Cab, 5" exhaust, volant air intake, BD exhaust brake