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: Obd drive mode
Performing the Drive Mode inspects the OBD system for proper operation.
The Drive Mode must be performed to ensure that no additional DTCs are
present.
During Drive Mode, the following systems are inspected:
- Oxygen sensor (HO2S)
- Oxygen sensor heater
- Catalytic converter (TW ...
Mazda 6 Owners Manual: Bright-Metal Maintenance
Use tar remover to remove road tar and insects. Never do this with a knife
or similar tool.
To prevent corrosion on brightmetal surfaces, apply wax or chrome preservative
and rub it to a high luster.
During cold weather or in coastal areas, cover bright-metal parts with a
coating of ...