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: Battery Maintenance
To get the best service from a battery:
Keep it securely mounted.
Keep the top clean and dry.
Keep terminals and connections clean, tight, and coated with petroleum jelly
or terminal grease.
Rinse off spilled electrolyte immediately with a solution of water and baking
soda.
If th ...
Mazda 6 Owners Manual: Dtc c1095, c1096
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...