Jeep 2012 Grand Cherokee SRT - Owner Manual - Manual (Page 471)

FUEL REQUIREMENTS
6.4L Engine
The 6.4L engine is designed to meet all
emissions regulations and provide excel-
lent fuel economy and performance when
using high-quality premium unleaded
gasoline with an octane rating of 91 or
higher.
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 World-
wide Fuel Charter, WWFC) which define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasolines that meet the WWFC speci-
fications if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “reformulated gasoline.”
Reformulated gasolines contain oxygenates and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The manufacturer supports the use of reformulated gaso-
lines. Properly blended reformulated gasolines will pro-
vide excellent performance and durability of engine and
fuel system components.
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