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 seal replacement
1. Drain the ATF. (See AUTOMATIC TRANSAXLE FLUID (ATF) REPLACEMENT.)
Caution
The oil seal is easily damaged by the sharp edges of the drive
shaft splines. Do not let the splines contact the oil seal.
2. Remove the drive shaft. (See DRIVE SHAFT REMOVAL/INSTALLATION.)
3. Remove the oil sea ...
Mazda 6 Owners Manual: Hold switch inspection
Operating Inspection
1. Turn the ignition switch to ON (engine OFF).
2. Verify that the HOLD indicator light is not illuminated. Depress the HOLD
switch and verify that the HOLD indicator light illuminates.
If not as specified, inspect the terminal voltage of the HOLD switch.
Voltage Insp ...