of 87. The use of premium gasoline is not recommended,
as it will not provide any benefit over regular gasoline in
these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such
as hard starting, stalling, and hesitations. If you experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle. Over 40 auto
manufacturers worldwide have issued and endorsed
consistent gasoline specifications (the Worldwide Fuel
Charter, WWFC) which define fuel properties necessary
to deliver enhanced emissions, performance, and dura-
bility for your vehicle. The manufacturer recommends
the use of gasoline that meet the WWFC specifications if
they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline”.
Reformulated gasoline contain oxygenates and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The use of reformulated gasoline is recommended. Prop-
erly blended reformulated gasoline will provide im-
proved performance and durability of engine and fuel
system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as ethanol.
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