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: Car-navigation unit removal/installation
1. Disconnect the negative battery cable.
2. Remove the glove compartment.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Car-navigation Unit Installation Note
Insert the car-navigation unit bracket into the dashboard member hole, and
with the c ...
Mazda 6 Owners Manual: Purge solenoid valve inspection
Airflow Inspection
Note
Perform the following test only when directed.
1. Disconnect the negative battery cable.
2. Remove the purge solenoid valve. (See PURGE SOLENOID VALVE
REMOVAL/INSTALLATION.)
3. Inspect airflow between the ports under the following conditions.
If not as specifi ...