RAM 2500 Truck 2WD L6-6.7L DSL Turbo (2010)
Coolant: Description and Operation
HOAT COOLANT
WARNING: Antifreeze is an ethylene-glycol base coolant and is harmful if swallowed or inhaled. If swallowed, drink two glasses of water and
induce vomiting. If inhaled, move to fresh air area. Seek medical attention immediately. Do not store in open or unmarked
containers. Wash skin and clothing thoroughly after coming in contact with ethylene-glycol. Keep out of reach of children. Dispose
of glycol based coolant properly, contact your dealer or government agency for location of collection center in your area. Do not
open a cooling system when the engine is at operating temperature or hot under pressure, personal injury can result. Avoid
radiator cooling fan when engine compartment related service is performed, personal injury can result.
CAUTION: Use of Propylene-Glycol based coolants is not recommended, as they provide less freeze protection and less corrosion protection.
The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder head area near the exhaust valves
and engine block. Then coolant carries the heat to the radiator where the tube/fin radiator can transfer the heat to the air.
The use of aluminum cylinder blocks, cylinder heads, and water pumps require special corrosion protection. Mopar(R) Antifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equivalent ethylene-glycol base coolant with organic corrosion inhibitors (called HOAT, for Hybrid
Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% ethylene-glycol and
50% distilled water to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly
mixed coolant solution.
CAUTION: Mopar(R) Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MS-9769) may not be mixed with any other type of antifreeze.
Mixing of coolants other than specified (non-HOAT or other HOAT) may result in engine damage that may not be covered under
the new vehicle warranty, and decreased corrosion protection.
COOLANT PERFORMANCE
The required ethylene-glycol and water mixture depends upon climate and vehicle operating conditions. The coolant performance of various mixtures
follows:
Pure Water- Water can absorb more heat than a mixture of water and ethylene-glycol. This is for purpose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol - The corrosion inhibiting additives in ethylene-glycol need the presence of water to dissolve. Without water, additives
form deposits in system. These act as insulation causing temperature to rise to as high as 149°C (300°F). This temperature is hot enough to melt plastic.
The increased temperature can result in severe engine damage. In addition, 100 percent ethylene-glycol freezes at -22°C (-8°F).
50/50 Ethylene-Glycol and Water - Is the recommended mixture, it provides protection against freezing to -37°C (-34°F). The antifreeze
concentration must always be a minimum of 44 percent, year-round in all climates. If percentage is lower, engine parts may be eroded by cavitation.
Maximum protection against freezing is provided with a 68 percent antifreeze concentration, which prevents freezing down to -67.7°C (-90°F). A
higher percentage will freeze at a warmer temperature. Also, a higher percentage of antifreeze can cause the engine to overheat because specific heat of
antifreeze is lower than that of water.
CAUTION: Richer antifreeze mixtures cannot be measured with normal field equipment and can cause problems associated with 100 percent
ethylene-glycol.
