Page 16 of 360

ENGINE BREAK-IN RECOMMENDATIONS
The diesel engine does not require a break-in period due
to its construction. Normal operation is allowed, provid-
ing the following recommendations are followed:
•Warm up the engine before placing it under load.
•Do not operate the engine at idle for prolonged
periods.
•Use the appropriate transmission gear to prevent
engine lugging.
•Observe vehicle oil pressure and temperature indica-
tors.
•Check the coolant and oil levels frequently.
•Vary throttle position at highway speeds when carry-
ing or towing significant weight.NOTE:Light duty operation such as light trailer towing
or no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy and
power may be seen at this time.
The engine oil installed in the engine at the factory is a
high-quality energy conserving type lubricant. Oil
changes should be consistent with anticipated climate
conditions under which vehicle operations will occur.
The recommended viscosity and quality grades are
shown under “Fluids, Lubricants and Genuine Parts”,
under “Maintaining Your Vehicle” in this manual. NON-
DETERGENT OR STRAIGHT MINERAL OILS MUST
NEVER BE USED.
14 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 
     
        
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CAUTION!(Continued)
•DO NOT OVERFILL. DEF will freeze below 12ºF
(-11ºC). The DEF system is designed to work in
temperatures below the DEF freezing point, how-
ever, if the tank is overfilled and freezes, the
system could be damaged.
•When DEF is spilled, clean the area immediately
with water and use an absorbent material to soak
up the spills on the ground.
•Do not attempt to start your engine if DEF is
accidentally added to the diesel fuel tank as it can
result in severe damage to your engine, including
but not limited to failure of the fuel pump and
injectors.
3. Stop filling the DEF tank immediately when any of the
following happen: DEF stops flowing from the fill
bottle into the DEF tank, DEF splashes out the filler
neck, or a DEF pump nozzle automatically shuts off.4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C), your vehicle
is equipped with an automatic DEF heating system. This
allows the DEF injection system to operate properly at
temperatures below 12°F (-11°C). If your vehicle is not in
operation for an extended period of time with tempera-
tures below 12°F (-11°C), the DEF in the tank may freeze. If
the tank is overfilled and freezes, it could be damaged.
Therefore, do not overfill the DEF tank.
Extra care should be taken when filling with portable
containers to avoid overfilling. Note the level of the DEF
gauge in your instrument cluster. On pickup applications,
you may safely add a maximum of 2 gallons of DEF from
portable containers when your DEF gauge is reading ½ full.
98 STARTING AND OPERATING 
     
        
        Page 263 of 360

3. Stop filling the DEF tank immediately when any of the
following happen: DEF stops flowing from the fill
bottle into the DEF tank, DEF splashes out the filler
neck, or a DEF pump nozzle automatically shuts off.
4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C), your vehicle
is equipped with an automatic DEF heating system. This
allows the DEF injection system to operate properly at
temperatures below 12°F (-11°C). If your vehicle is not in
operation for an extended period of time with tempera-
tures below 12°F (-11°C), the DEF in the tank may freeze. If
the tank is overfilled and freezes, it could be damaged.
Therefore, do not overfill the DEF tank.
Extra care should be taken when filling with portable
containers to avoid overfilling. Note the level of the DEF
gauge in your instrument cluster. On pickup applications,you may safely add a maximum of 2 gallons of DEF from
portable containers when your DEF gauge is reading ½ full.
On Chassis Cab applications a maximum of 2 gallons may
be added when the DEF gauge is reading ¾ full.
TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer, carefully
review this information to tow your load as efficiently
and safely as possible.
To maintain the New Vehicle Limited Warranty coverage,
follow the requirements and recommendations in this
manual concerning vehicles used for trailer towing.
4
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