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: Tire house trim removal/installation
4SD
1. Remove the rear scuff plate.
2. Remove the rear seat side.
3. Remove the fastener.
4. Pull the tire house trim upward, then disengage clips A from the body, and
remove the tire house trim.
5. Install in the reverse order of removal.
5HB
1. Remove the rear scuff plate.
2. Pull the ...
Mazda 6 Owners Manual: Rear Cross Traffic Alert (RCTA) (Some models)
The Rear Cross Traffic Alert (RCTA) system is designed to assist the driver in
checking the area to the rear of the vehicle on both sides while the vehicle is
reversing by alerting the driver to the presence of vehicles approaching the rear
of the vehicle.
The Rear Cross Traffic Alert (RCTA) ...