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: Wheel hub bolt replacement
1. Remove the hub bolt using the SSTs.
Note
If the dust cover interferes with the wheel hub bolt and the wheel
hub bolt cannot be removed, tap the part shown in the figure with a chisel
lightly and bend the processing point back to the steering knuckle side.
2. Install the hub bolt i ...
Mazda 6 Owners Manual: Multi-Information Display and INFO Switch (Some models)
The multi-information display indicates the following information.
Odometer
Trip meter
Engine coolant temperature gauge
Fuel gauge
Outside temperature
Distance-to-empty
Average fuel economy
Current fuel economy
Maintenance Monitor
...