Vehicles with catalytic converters or oxygen sensors must use ONLY UNLEADED FUEL, which will reduce exhaust emissions and keep spark plug fouling to a minimum.
This vehicle will perform best with fuel listed in the table.

* U.S. federal law requires that octane ratings be posted on gasoline station pumps.
Fuel with a rating lower than 87 octane (91 RON) will negatively affect the emission control system performance and could also cause engine knocking and serious engine damage.
CAUTION
Leaded fuel is harmful to the catalytic converter and oxygen sensors and will lead to deterioration of the emission control system and or failures.
Gasoline blended with oxygenates such as alcohol or ether compounds are generally referred to as oxygenated fuels. The common gasoline blend that can be used with your vehicle is ethanol blended at no more than 10 %. Gasoline containing alcohol, such as ethanol or methanol, may be marketed under the name "Gasohol".
Vehicle damage and drivability problems resulting from the use of the following may not be covered by the warranty.
Emission Control SystemMazda 6 Owners Manual: Selector lever disassembly/assembly
1. Disassemble in the order shown in the figure.
2. Assemble in the reverse order of disassembly.
Connector Disassembly Note
1. Insert a thin piece of metal from the terminal side of the connector, and
press down the terminal locking tab.
2. Pull the terminal out of the connector. ...
Mazda 6 Owners Manual: Storage Compartments
WARNING
Keep storage boxes closed when driving: Driving with the storage
boxes open is dangerous. To reduce the possibility of injury in an accident or a
sudden stop, keep the storage boxes closed when driving.
Do not put articles in storage spaces with no lid: Putting articles
in storage sp ...