Fuel and Exhaust Gas Precautions
Fuel to Use
Vehicles equipped with a catalytic converter or oxygen sensors must use UNLEADED FUEL ONLY, which reduces exhaust emissions and minimizes spark plug fouling.
This Mazda vehicle will deliver optimum performance with the fuel listed in the table below.

* U.S. federal law requires gasoline pumps to display the octane rating.
Fuel with an octane rating lower than 87 (91 RON) may reduce the effectiveness of the emission control system. It may also cause engine knock and engine damage.
WARNING
- USE UNLEADED FUEL ONLY. Leaded fuel damages the catalytic converter and oxygen sensors, causing deterioration of the emission control system and/or malfunctions.
- This vehicle cannot use oxygenated fuels containing more than 10% ethanol by volume. The vehicle may be damaged if the ethanol percentage exceeds this specification, or if the gasoline contains methanol. Stop using any gasohol if engine performance decreases.
- Never add fuel system additives. Doing so could damage the emission control system. Contact an authorized Mazda dealer for details.
Gasoline blended with oxygenates such as alcohol or ether blends is generally called oxygenated fuel. The common gasoline blend that can be used in this vehicle is ethanol blended at 10% or less. Gasoline containing alcohol, such as ethanol or methanol, is sold under the name "Gasohol".
Vehicle damage and driving problems resulting from the use of the following fuels may not be covered by the manufacturer's warranty.
- Gasohol containing more than 10% ethanol.
- Gasoline or gasohol containing methanol.
- Leaded gasoline or leaded gasohol.
Emission Control System
Your vehicle is equipped with an emission control system (the catalytic converter is part of this system) that complies with applicable exhaust emission laws.
WARNING
Never park on or near flammable materials:
Parking on flammable materials, such as dry grass, is dangerous. Even when the engine is off, the exhaust system remains very hot after normal use and can ignite flammable materials.
This could result in serious injury or death.
WARNING
Failure to observe the following precautions may cause lead to deposit on the catalyst inside the catalytic converter, or cause the catalytic converter to become very hot. This will damage the converter and result in poor performance.
- USE UNLEADED FUEL ONLY.
- Do not drive this Mazda vehicle if it shows signs of malfunction.
- Do not coast with the ignition switched off.
- Do not go down steep hills in gear with the ignition switched off.
- Do not run the engine at high idle speed for more than 2 minutes.
- Do not modify the emission control system. All inspections and adjustments must be performed by a qualified technician.
- Do not attempt to start the vehicle by pushing or towing it.
NOTE
- Under US federal law, any modification to the original emissions control system before the first sale and registration of such a vehicle is subject to penalties. In some states, such modifications made to used vehicles are also subject to penalties.
- When the engine is stopped, the sound of a valve opening and closing may be heard at the rear right side of the vehicle. This does not indicate a malfunction. This vehicle is equipped with a self-check system that operates after the engine is stopped.
Engine exhaust gas (Carbon monoxide)
WARNING
Do not drive the vehicle if you smell exhaust fumes inside the vehicle:
Exhaust gas is dangerous. It contains carbon monoxide (CO), which is colorless, odorless and extremely toxic. If inhaled, it can cause loss of consciousness and death. If you smell exhaust fumes inside the vehicle, keep all windows open and consult an authorized Mazda dealer immediately.
Do not run the engine in an enclosed area:
Running the engine in an enclosed area, such as a garage, is dangerous. Exhaust gas containing carbon monoxide, an extremely toxic gas, can easily enter the passenger compartment. This may result in loss of consciousness or even death.
Open the windows or adjust the heating or cooling system to bring in fresh air when the engine is idling:
Exhaust gas is dangerous. When the vehicle is stationary with the windows closed and the engine idling for a long period, even in an area that is not enclosed, exhaust gas containing carbon monoxide, an extremely toxic gas, can easily enter the passenger compartment. This may result in loss of consciousness or even death.
Clear snow from under and around the vehicle, especially the exhaust pipe, before starting the vehicle:
Running the engine while the vehicle is stationary in deep snow is dangerous. The exhaust pipe may become blocked by snow, causing exhaust gas to enter the passenger compartment. Since exhaust gas contains carbon monoxide, an extremely toxic gas, anyone in the vehicle may lose consciousness or even die.
Test yourself
A quick Mazda 6 quiz: every answer comes with an explanation and a link to the manual page.