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: Abs (abs/tcs) or dsc hu/cm configuration
1. Connect the WDS or equivalent to the DLC-2.
2. Input vehicle information following the direction on the WDS or equivalent
screen.
3. Select Module programming.
4. Select Programmable module installation.
5. Select ABS/TCS.
6. Retrieve DTCs by the WDS or equivalent, then verify that there ...
Mazda 6 Owners Manual: Intermittent concern troubleshooting
Vibration Method
1. If malfunction occurs or becomes worse while driving on a rough road or
when engine is vibrating, perform the steps below.
Note
There are several reasons vehicle or engine vibration could cause
an electrical malfunction. Some of the things to check for are:
...