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: Crankshaft position (ckp) sensor removal/installation
Removal
1. Perform the following procedure to making the working space.
(1) Remove the Front wheel (RH).
(2) Remove the splash shield.
2. Disconnect the CKP sensor connector.
3. Remove the installation bolts to remove the CKP sensor.
Installation
Caution
When foreign material such a ...
Mazda 6 Owners Manual: Crankshaft position (ckp) sensor inspection
Note
Perform the following inspection only when directed.
Resistance Inspection
1. Disconnect the CKP sensor connector.
2. Measure the resistance between CKP sensor terminals A and B using an
ohmmeter.
If not as specified, replace the CKP sensor.
If CKP sensor resistance is okay, bu ...