Dodge ram truck 3500 1996 Service Manual page 1236

14 - 2 FUEL SYSTEM
BR
G E N E R A L
INFORMATION
(Continued)
FUEL REQUIREMENTS
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
should be reported to your dealer immediately.
Engine damage resulting from operating with a
heavy spark knock may not be covered by the new
vehicle warranty.
In addition to using unleaded gasoline with the
proper octane rating, gasolines that contain deter­
gents, corrosion and stability additives are recom­
mended. Using gasolines, that have these additives
will help improve fuel economy, reduce emissions,
and maintain vehicle performance. Generally, pre­
mium unleaded gasolines contain more additive than
regular unleaded.
Poor quality gasoline can cause problems such as
hard starting, stalling, and stumble. I f you experi­
ence these problems, try another brand of gasoline
before considering service for the vehicle.
GASOLINE/OXYGENATE BLENDS
Some fuel suppliers blend gasoline with materials
that contain oxygen such as alcohol, MTBE (Methyl
Tertiary Butyl Ether) and ETBE (Ethyl Tertiary
Butyl Ether). Oxygenates are required in some areas
of the country during winter months to reduce carbon
monoxide emissions. The type and amount of oxygen­
ate used in the blend is important.
The following are generally used in gasoline
blends:
Ethanol - (Ethyl or Grain Alcohol) properly
blended, is used as a mixture of 10 percent ethanol
and 90 percent gasoline. Gasoline blended with etha­
nol may be used in your vehicle.
Methanol - (Methyl or Wood Alcohol) is used in a
variety of concentrations when blended with
unleaded gasoline. You may find fuels containing 3
percent or more methanol along with other alcohols
called cosolvents.
Do not use gasolines containing Methanol.
Use of methanol/gasoline blends may result in
starting and driveability problems and damage criti­
cal fuel system components.
Problems that are the result of using methanol/
gasoline blends are not the responsibility of Chrysler
Motors and may not be covered by the new vehicle
warranty.
M T B E / E T B E - Gasoline and MTBE (Methyl Ter­
tiary Butyl Ether) blends are a mixture of unleaded
gasoline blended and up to 15 percent MTBE. Gaso­
line and ETBE (Ethyl Tertiary Butly Ether) are
blends of gasoline and up to 17 percent ETBE. Gas­
oline blended with MTBE or ETBE may be used i n
your vehicle.
Many gasolines are now being blended that con­
tribute to cleaner air, especially in those areas of the
country where pollution levels are high. These new
blends provide a cleaner burning fuel and some are
referred to as reformulated gasoline.
Reformulated Gasoline
Many areas of the country are requiring the use of
cleaner-burning fuel referred to as Reformulated
Gasoline. Reformulated gasolines are specially
blended to reduce vehicle emissions and improve air
quality.
Chrysler Corporation strongly supports the use of
reformulated gasolines whenever available. Although
your vehicle was designed to provide optimum perfor­
mance and lowest emissions operating on high qual­
ity unleaded gasoline, i t will perform equally well
and produce even lower emissions when operating on
reformulated gasoline.
Materials Added to Fuel
Indiscriminate use of fuel system cleaning agents
should be avoided. Many of these materials intended
for gum and varnish removal may contain active sol­
vents of similar ingredients that can be harmful to
fuel system gasket and diaphragm materials.
FUEL REQUIREMENTS—DIESEL ENGINE
WARNING: Do not use alcohol or gasoline a s a fuel
blending agent. They can be unstable under certain
conditions and hazardous or explosive when mixed
with diesel fuel.
Use good quality diesel fuel from a reputable sup­
plier i n your Dodge truck. For most year-round ser­
vice, number 2 diesel fuel meeting ASTM
specification D-975 will provide good performance. I f
the vehicle is exposed to extreme cold (below 0°F/-
18°C), or is required to operate at colder-than-normal
conditions for prolonged periods, use climatized No. 2
diesel fuel or dilute the No. 2 diesel fuel with 50%
kerosene or No. 1 diesel fuel. This will provide better
protection from fuel gelling or wax-plugging of the
fuel filters.
Diesel fuel is seldom completely free of water. To
prevent fuel system trouble, drain the accumulated
water from the fuel/water separator using the fuel/
water separator drain provided. I f you buy good-qual­
ity fuel and follow the cold-weather advice above, fuel
conditioners should not be required in your vehicle I f
available in your area, a high cetane "premium" die­
sel fuel may offer improved cold starting and
warm-up performance