I have no idea how this works - but I have questions.....
Diesel in the US now can cost as low as $1/70 - found in TX on Gas Buddy recently - could be cheaper elsewhere.
I do not know if LSD is still produced in the US since most vehicles now require ULSD.
We recently paid $13.77MX per liter for diesel in Mexico.
By the recent exchange rate a peso is worth about 0.055 cents US.
So a liter is costs about .76 US.
3.78 liter per gallon so about $2.86US per gallon.
What is the wholesale price of US diesel as opposed to MX diesel?
If the big franchisees in MX can buy ULSD from the US for less than they can from Pemex would they be allowed to buy from the US? Seems that is what is going to happen April 1.
You may have noticed signs going up on many Pemex stations saying G500 Grupo Gasolineria or something similar. This is an association of franchisees which now includes between 800 to 1,000 Pemex stations. There is a website that explains more about fuel prices in Mexico and about G500. They will be able to buy fuel from suppliers other than Pemex but the price at the pump will still be set by the treasury of Mexico. There will be a high and low price and they can set their pump price somewhere between the high and low. What G500 will be able to do is use there immense buying power to purchase and transport at low cost. I did not see anything about ULSD but if they can buy for less in the US maybe they would just buy for the best price. If only ULSD is produced in the US then that could be what G500 will have. I have no idea. As stated by others above - there is no reason for Mexico to have ULSD as it is not required by vehicles purchased in Mexico - trucks in Mexico still use LSD. But does the US still produce LSD? Why would they since it is not used in the US? But if there was demand for LSD from Mexico and LSD is cheaper to produce than ULSD would refineries in the US produce LSD just for the Mexican market? Lots of questions.
Here are a couple of websites where some searching can be done to try to learn more.
https://g500.mx/
http://www.dineroenimagen.com/2015-10-28/63719
I used Google Translate to enable reading of these websites.