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: Air bleeding
1. Inspect the fluid level. (See POWER STEERING FLUID INSPECTION.)
2. Jack up the front of the vehicle and support it on safety stands.
3. Turn the steering wheel fully to the left and right several times with the
engine not running.
4. Reinspect the fluid level.
If it has dropped, add flui ...
Mazda 6 Owners Manual: Manual transaxle removal/installation
1. Remove the battery, battery tray and battery bracket.
2. Remove the air cleaner compornent. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
3. Remove the wheels, tires and splash shields.
4. Remove the under cover.
5. Remove the steering gear and power steering pipe. (See STEERING GEAR AND
...