Methylcyclopentadienyl Manganese Tricarbonyl (Mmt) In Gasoline; Fuel System Cautions - Jeep Wrangler Owner's Manual

278 TECHNICAL SPECIFICATIONS
M
ETHYLCYCLOPENTADIENYL
M T
ANGANESE RICARBONYL
G
ASOLINE
MMT is a manganese containing metallic additive that is
blended into some gasolines to increase octane. Gasoline
blended with MMT provides no performance advantage
beyond gasoline of the same octane number without
MMT. Gasoline blended with MMT reduces spark plug life
and reduces emission 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 the gasoline retailer whether or
not the gasoline contains MMT.
F S
UEL YSTEM
(MMT) I
N
Follow these guidelines to maintain your vehicle's
performance:
 The use of leaded gasoline is prohibited by law. Using
leaded gasoline can impair engine performance and
damage the emissions control system.
 An out-of-tune engine or certain fuel or ignition
malfunctions can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact an authorized dealer for service assistance.
 The use of fuel additives, which are now being sold
as octane enhancers, is not recommended. Most of
these products contain high concentrations of meth-
anol. Fuel system damage or vehicle performance
problems resulting from the use of such fuels or addi-
tives is not the responsibility of the manufacturer
and may void or not be covered under the New
Vehicle Limited Warranty.
C
AUTIONS
CAUTION!
NOTE:
Intentional tampering with the emissions control system
can result in civil penalties being assessed against you.