Great information, very informative and very useful as I plan one day to visit the rest of South America, as an Englishman now living in Cozumel México, I can say that Pemex do now accept credit cards, but it is safer with cash, as you can get scammed.
Great resource. I'll be heading north from Brazil in August 2017 so I am currently consuming as much information as I can to prepare for the trip! I'll be making use of many of your tips and suggestions!
Guys like you are treasures who take the time to share your experience and write it down for guys like me. I am crossing the border this October 2016 for 8 months of adventure style motoing and travel. Thanks for the resource amigo!