Dodge 2004 HB Durango - Manual (Page 244)

MMT In Gasoline
MMT is a manganese-containing metallic additive that is
blended into some gasoline to increase octane. Gasolines
blended with MMT provide no performance advantage
beyond gasolines of the same octane number without
MMT. Gasolines blended with MMT reduce spark plug
life and reduce emission system performance. We recom-
mend that gasolines free of MMT be used in your vehicle.
The MMT content of gasoline may not be indicated on
the gasoline pump; therefore, you should ask your gaso-
line retailer whether or not his/her gasoline contains
MMT.
It is even more important to look for gasolines without
MMT in Canada because MMT can be used at levels
higher than allowed in the United States. MMT is pro-
hibited in Federal and California reformulated gasolines.
Sulfur In Gasoline
If you live in the northeast United States, your vehicle
may have been designed to meet California low emission
standards with Cleaner-Burning California reformulated
gasoline with low sulfur. If such fuels are not available in
states adopting California emission standards, your ve-
hicles will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be adversely affected. Gasoline sold outside of
California is permitted to have higher sulfur levels which
may affect the performance of the vehicle’s catalytic
converter. This may cause the Check Engine or Service
Engine Soon light to illuminate. We recommend that you
try a different brand of unleaded gasoline having lower
sulfur to determine if the problem is fuel related prior to
returning your vehicle to an authorized dealer for ser-
vice.
244 STARTING AND OPERATING