Every drop of Pemex Premium sold in the country is U.S. refined. Every drop of Manga sold in Baja California B.C. is refined in the U.S. Every drop of Ultra Low Sulfur Diesel is refined in the U.S. Pemex tries to keep it a secret but a significant percentage (but less than 30%) of Magna comes from the north.
Furthering this - you might want to research the percentage of base bottom foodstuffs that are imported. Rice, beans, and masa.
The reliance on imported basic foodstuffs is key to unacceptable percentage rises in peso cost of the most elementary survival foods. They key is avoiding toll road costs. Have fun! Price a 5-axle round trip toll cost from say Nogales to Puerto Vallarta. Or from Mexico DF to Guadalajara. The regional masa production facilities a person sees as they journey is to avoid transportation costs. The same thing applies to the fields of corn surrounding the factory.
The cost of transporting food from the USA is horrendous. I know few of you utilize Mexican packaging services. Here is a clue: Do you know how tiny and how light a carburetor rebuilding kit is? It is shipped by envelope! Less than four ounces! ESTAFETA charged me $280MN to ship it 2,000 Km. Even using 19.5 pesos to the dollar exchange rate, this comes out to $14.36 dlls USA. Had I sent it by regular post it would have never made it. I have stuffed more than a DOZEN envelopes with a blank sheet of paper and mailed them via the same route. THREE (3)! envelopes arrived and yes they had the codigal postal correct and the recipient has an apto.
Pemex is a bureaucracy. It operates exactly like a true bloated bureaucracy should. It takes NINETY PLUS separate Pemex on site inspections plus THOUSANDS of pages of paperwork to get a franchise approved so the station can open. Then comes periodic inspections. This insanity is a key as to why many station owners insist on rigging their pumps to increase profit. A tiny gasolinera that would cost perhaps $180,000 US to construct, instead costs $400,000 because Pemex has to approve every step and every contractor. Take fire extinguishers. unless the station franchisee purchases "approved" fire extinguishers from one certain proveedor the process halts right there. Even though the model number and brand is exactly the same. Lights and bathroom fixtures, everything in the station has to be "qualified". This is not a safety issue, it is demanding the franchisee purchase from selected vendors.
Gasolinera regional "cartels" exist. Believe it. If a particular franchisee decides to maintain 0% error in their dispensers, pressure is exerted from the "cartel" an unorganized group of anywhere from 4 to who knows (30?) regional franchisees. What they do is slip the leader of the PROFECO verification team a little mordida usually $10,000+ pesos. What the leader does is slow the verification down. It usually takes PROFECO an hour or so to verify dispensers. But with the "tip" errors are found. Confusion reigns. The hour-long inspection will take all day. And there is nothing the station owner can do about it. He is out of business for 24+ hours. A "Denuncia" of a PROFECO team leader can lead to a jail sentence for the station owner if the denuncia cannot be proven.
This isn't some BS krap - this is the real Mexico. Some gringos cannot handle it. Of course it isn't right. But what does a person do? Get angry? Wring their hands? Threaten to never travel or live down here? Or accept reality with a clear eye and manage to do the best they can with what they have? Your call...