Jeep Grand Cherokee 2015, Operating Information Manual, Page: 320 / 878

Poor quality gasoline can cause problems such
as hard starting, stalling and stumble. If you
experience these problems, try another brand
of gasoline before considering service for the
vehicle.
2.4L Engine
These engines are designed to meet all emis-
sions regulations and provide excellent fuel
economy and performance when using high-
quality unleaded gasoline with a minimum Re-
search Octane Number (RON) of 91.
3.2L Engine
The 3.2L engine is designed to meet all emis-
sions regulations and provide satisfactory fuel
economy and performance when using high
quality unleaded gasoline having a minimum
octane rating of 91 Research Octane Number
(RON). The manufacturer recommends the use
of 93 Research Octane Number (RON) for
optimum 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 ser-
vice is required. Poor quality gasoline can
cause problems such as hard starting, stalling,
and hesitations. If you experience these symp-
toms, try another brand of gasoline before con-
sidering service for the vehicle.
Methanol
(Methyl) is used in a variety of concentrations
when blended with unleaded gasoline. You may
find fuels containing 3% or more methanol
along with other alcohols called cosolvents.
Problems that result from using methanol/
gasoline are not the responsibility of the manu-
facturer. While MTBE is an oxygenate made
from Methanol, it does not have the negative
effects of Methanol.
CAUTION!
Do not use gasolines containing Methanol.
Use of these blends may result in starting
and drivability problems and may damage
critical fuel system components.
Ethanol
The manufacturer recommends that your ve-
hicle be operated on fuel containing no more
than 10% ethanol. Purchasing your fuel from a
reputable supplier may reduce the risk of ex-
ceeding this 10% limit and/or of receiving fuel
with abnormal properties. It should also be
noted that an increase in fuel consumption
should be expected when using ethanol-
blended fuels, due to the lower energy content
of ethanol. Problems that result from using
methanol/gasoline or E-85 ethanol blends are
not the responsibility of the manufacturer.
CAUTION!
Use of fuel with Ethanol content higher than
10% may result in engine malfunction, start-
ing and operating difficulties, and materials
degradation. These adverse effects could
result in permanent damage to your vehicle.
Clean Air Gasoline
Many gasolines are now being blended to con-
tribute to cleaner air, especially in those areas
where air pollution levels are high. These new
blends provide a cleaner burning fuel and some
are referred to as “reformulated gasoline.”
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