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: Customer Assistance (U.S.A.)
Your complete and permanent satisfaction is our business. We are here to serve
you. All Authorized Mazda Dealers have the knowledge and the tools to keep your
Mazda vehicle in top condition.
If you have any questions or recommendations for improvement regarding the service
of your Mazda vehic ...
Mazda 6 Owners Manual: Throttle position (tp) sensor inspection
Note
Perform the following inspection only when directed.
Resistance Inspection
1. Perform the following test only when directed.
If as specified but TP PID value is out of specification, inspect
resistance of TP sensor.
If not as specified, inspect the following:
- Accelerato ...