All the gas stations are full serve. Although most gas station attendants are honest, you should always watch to make sure they reset the numbers to OOOOO before pumping the gas.

Playa del Carmen and Mayan Riviera

  I heard there was no unleaded gas

There is definitely unleaded gas ("sin plomo" in Spanish), although premium/high octane gas is sold in all Gas Stations. To get the good stuff, get on the highway towards Cancun. 

The gas station is on the left side. There are gas stations on the highway at Puerto Moreles, Playa del Carmen and Tulum (also one on the island of Cozumel). 

To be safe, don't let your tank get down below 1/4. The gas stations are all run by PEMEX (PEtroleos MEXicanos) the government monopoly. The gasoline prices are the same everywhere in Mexico. Credit cards are NOT accepted.

All the gas stations are full serve. Although most gas station attendants are honest, you should always watch to make sure they reset the numbers to OOOOO before pumping the gas. Watch the guy, say "lleno, por favor" to fill up, then tip him a few pesos. 

Of course tip more if you have him check the oil or tires. With the oil, make sure the oil container is new and full before he pours it in. The gas stations sell maps,  snacks, soda drinks, you can find with a green and red logo by PEMEX

There are Gas Stations in the following cities in the Yucatan peninsula: 

Cancun, 

Puerto Morelos, 

Playa de Carmen, 

Tulum,

Carrillo Puerto, 

Chetumal, 

Chemax, 

Valladolid, 

Piste ( Chichen Itza ) 

Merida.

Si usted viaja por la Península de Yucatán, podrá abastecerse de gasolina en las ciudades de:

Cancún, 

Puerto Morelos, 

Playa del Carmen, 

Tulúm (cierra a las 8 p.m.), 

Carrillo Puerto, 

Chetumal, 

Chemax (cierra a las 8 p.m.), 

Valladolid, 

Pisté 

There are gas stations on the highway at Cancun Puerto Moreles, Playa del Carmen, Tulum and Cozumel in Riviera Maya.