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: If a Warning Light Turns On or Flashes
If any warning light turns on/flashes, take appropriate action for each light.
There is no problem if the light turns off, however if the light does not turn off
or turns on/flashes again, consult an Authorized Mazda Dealer.
The warning contents can be verified on the center display.
1. If the ...
Mazda 6 Owners Manual: A/c unit removal/installation
1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See RECOVERY.) (See CHARGING.)
3. Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT.)
4. Remove the dashboard. (See DASHBOARD REMOVAL/INSTALLATION.)
5. Remove the theft-deterrent control module. (See ...