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: Basic power window system inspection
Manual Mode Function Inspection
Automatic Mode Function Inspection
Automatic Window Return Function Inspection
IG OFF Timer Function Inspection
Two-step Down Function Inspection
The distance the door glass opens can be changed using the two-step down
function. (Approximately 20- ...
Mazda 6 Owners Manual: Torque formulas
When using a torque wrench-SST or equivalent combination, the
written torque must be recalculated due to the extra length that the SST
or equivalent adds to the torque wrench.
Recalculate the torque using the following formulas. Choose the formula that
applies to you.
A : The leng ...