catalytic converter MAZDA MODEL 3 4-DOOR 2018 Owners Manual

Fuel and Engine Exhaust Precautions
▼Fuel Requirements
Vehicles with catalytic converters or oxygen sensors must use O
NLY UNLEADED FUEL,
which will reduce exhaust emissions and keep spark plug fouling to a minimum.

This vehicle will perform best w ith fuel listed in the table.
Fuel
Octane Rating* (Anti-knock index)
Regular unleaded fuel 87 [(R
M)/2 method] or above (91 RON or above)
U.S. federal law requires that octane ratings be posted on gaso
line station pumps.
Fuel with a rating lower than 87 octane (91 RON) will negativel y affect the emission control
system performance and could also cause engine knocking and ser ious engine damage.
CAUTION
USE ONLY UNLEADED FUEL.
Leaded fuel is harmful to th e catalytic converter and oxygen sensors and will lead to
deterioration of the emission control system and or failures.
 This vehicle can only use oxygenated fuels containing no more than 10 % ethanol by
volume. Damage to the vehicle may occur wh en ethanol exceeds this recommendation, or
if the gasoline contains any methanol. Stop using gasohol of any kind if your vehicle engine
is performing poorly.
 Never add fuel system additives, otherwise th e emission control system could be damaged.
Consult an Authorized Mazda Dealer for details.
Gasoline blended with oxygenates such as alcohol or ether compo unds 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 conta ining 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.
Gasohol containing mo re than 10 % ethanol.
Gasoline or gasohol containing methanol.
Leaded fuel or leaded gasohol.
Before Driving
Fuel and Emission
3-25
Mazda3_8GE4-EA-17F_Edition1 2017-4-7 11:59:21

▼Emission Control System
This vehicle is equipped with an
emission control system (the catalytic converter is part of
this system) that enables the vehicle to comply with existing e xhaust emissions
requirements.
WA R N I N G
Never park over or near anything flammable:
Parking over or near anything flammable, such as dry grass, is dangerous. Even with the
engine turned off, the exhaust system remains very hot after normal use and could ignite
anything flammable. A resulting fire co uld cause serious injury or death.
CAUTION
Ignoring the following precautions could cause lead to accumulate on the catalyst inside the
converter or cause the converter to get very hot. Either condition will damage the converter
and cause poor performance.
USE ONLY UNLEADED FUEL.
 Do not drive your Mazda with any sign of engine malfunction.
 Do not coast with the ignition switched off.
 Do not descend steep grades in gear with the ignition switched off.
 Do not operate the engine at high idle for more than 2 minutes.
 Do not tamper with the emission control sy stem. All inspections and adjustments must be
made by a qualified technician.
 Do not push-start or pull-start this vehicle.
NOTE
Under U.S. federal law, any modification to the original-equipment emission control
system before the first sale and registration of a vehicle is subject to penalties. In some
states, such modification made on a used vehicle is also subject to penalties.
While the engine is off, the sound of a valve opening and closing can be heard at the rear
of the vehicle, however this does not indicate an abnormality. The vehicle has a
self-checking device and it oper ates while the engine is off.
Before Driving
Fuel and Emission
3-26
Mazda3_8GE4-EA-17F_Edition1 2017-4-7 11:59:21