Jeep Cherokee 2019, Owner'S Manual, Page: 515 / 636

CNG And LP Fuel System Modifications
Modifications that allow the engine to run on compressed
natural gas (CNG) or liquid propane (LP) may result in
damage to the engine, emissions, and fuel system compo-
nents. Problems that result from running CNG or LP are
not the responsibility of the manufacturer and may void or
not be covered under the New Vehicle Limited Warranty.
MMT In Gasoline
Methylcyclopentadienyl Manganese Tricarbonyl (MMT) is
a manganese-containing metallic additive that is blended
into some gasoline to increase octane. Gasoline blended
with MMT provides no performance advantage beyond
gasoline of the same octane number without MMT. Gaso-
line blended with MMT reduces spark plug life and
reduces emissions system performance in some vehicles.
The manufacturer recommends that gasoline without
MMT be used in your vehicle. The MMT content of
gasoline may not be indicated on the gasoline pump;
therefore, you should ask your gasoline retailer whether
the gasoline contains MMT. MMT is prohibited in Federal
and California reformulated gasoline.
Materials Added To Fuel
Besides using unleaded gasoline with the proper octane
rating, gasolines that contain detergents, corrosion and
stability additives are recommended. Using gasolines that
have these additives will help improve fuel economy,
reduce emissions, and maintain vehicle performance.
Designated TOP TIER Detergent Gaso-
line contains a higher level of detergents
to further aide in minimizing engine
and fuel system deposits. When avail-
able, the usage of TOP TIER Detergent
gasoline is recommended. Visit
www.toptiergas.com for a list of TOP
TIER Detergent Gasoline Retailers.
Indiscriminate use of fuel system cleaning agents should be
avoided. Many of these materials intended for gum and
varnish removal may contain active solvents or similar
ingredients. These can harm fuel system gasket and dia-
phragm materials.
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TECHNICAL SPECIFICATIONS 513