Chrysler 2008 Country - Manual (Page 381)

FUEL REQUIREMENTS
3.3L & 3.8L Gasoline Engine
All engines are designed to meet all emis-
sions regulations and provide excellent
fuel economy and performance when us-
ing high-quality unleaded “regular” gaso-
line having an octane rating of 87. The use
of premium gasoline is not recommended.
Under normal conditions, the use of premium gasoline
will not provide a benefit over high-quality regular
gasolines, and in some circumstances may result in
poorer performance.
4.0L Gasoline Engine
The 4.0L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline having an octane
range of 87 to 89. The manufacturer recommends the use
of 89 octane for optimum performance. The use of
premium gasoline is not recommended. Under normal
conditions, the use of premium gasoline will not provide
a benefit over high-quality regular and mid-grade gaso-
lines, and in some circumstances may result in poorer
performance.
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 experience these
symptoms, try another brand of “regular” gasoline be-
fore considering service for the vehicle.
STARTING AND OPERATING 379
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