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: Oil pan
OIL PAN REMOVAL/INSTALLATION
Warning
Hot engine and engine oil can cause severe burns. Turn off the
engine and wait until it and the engine oil have cooled.
1. Disconnect the negative battery cable.
2. Remove the under cover.
3. Drain the engine oil. (See ENGINE OIL REPLACEMENT.)
4. Re ...
Mazda 6 Owners Manual: Fuel Gauge
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the fuel level is low, and
turn an amber color. Refuel as soon as possible.
Refer to Taking Action.
NOTE
After refueling, it m ...