Pemex is the Mexican government’s monopoly gasoline and diesel fuel chain. There are two grades of gasoline currently available in Mexico – Magna Sin (unleaded) at 87 octane and Premium Magna Sin at 89 octane.
Gas prices vary all over Mexico.
Gasoline prices are significantly lower in border cities such as Tijuans, Mexicali, Nogalis, etc., when prices on the U.S. side are lower than the normal prices in Mexico. This is done to discourage Mexicans with border-crossing cards or visas from driving into the United States to buy the cheaper gasoline.
Gasoline is also less expensive in the state of Quintana Roo [Cancun – Mayan Riviera] because of 5% less tax.
Since early 2008 most Pemex stations in the more populated areas of Mexico have been accepting Visa and MasterCard. However it’s wise to ask first, because some stations (especially in rural areas) do not yet accept credit cards, or their card readers may not be functioning due to network problems.
Pemex stations accept U.S. currency.
The rule of thumb is when ever you see a gas station, fill-up. Do not enter the jungle with half a tank of gas unless you know exactly where you are going.
If you stick to main highways you will encounter frequent gas stations. Sometimes the station will not have any gas [usually around Merida or the Chiapas]. There will usually be something telling you not to bother driving in. No cars is generally a good indication that there is no gas.
All gas stations have attendants. Every gas station we have ever been in has a small convenience store and you will usually find someone who speaks English if you need help or directions. Some gas stations are quite popular with the locals and is a sort of hangout. At these stations expect many peddlers. There will sometimes be a pretty young girl who will have an old blind or crippled lady with her asking for money. Hand them a few pesos which you can be assured will go to the care and feeding of their family who may be undergoing difficulties beyond your imagination.