PRACTICE Modern coolants
PRACTICE Modern coolants not only vary in color, they differ significantly in composition too. From left to right, samples of: MOTOREX COOLANT M2.0, M3.0, M3.1, M4.0, M4.13, M5.0 and G48. NEW EMISSION STANDARDS TURNING UP THE HEAT ON COOLANTS Coolants and cooling system maintenance have taken on a new significance since the Euro 6 standard and “Final Tier 4” took effect. This is also borne out by stricter manufacturers’ requirements. Engine makers have applied many innovative technologies to meet the strictest emissions reduction standards of all time. These include various exhaust gas detoxification systems, including the now practically obligatory cooled exhaust gas recirculation, everlower production tolerances using innovative materials and sophisticated fuel metering systems. All in all, Euro 6 and “Final Tier 4” have led and continue to drive Hi-Tech in engine construction. HIGHER OPERATING TEMPERATURES Exhaust gas post-treatment technologies such as SCR, EGR, etc. require higher cooling system operating temperatures. At the same time, many cooling systems and their volume capacities have remained practically unchanged. Along with all the tasks the coolant is ex- pected to perform in the most recent generation of engines, it also has to stand up to the higher temperatures that come with exhaust gas recirculation. With operating temperatures 10 – 15 °C higher if not more, using the wrong coolant can cause the inhibitors (active ingredients) to break down. This can result in cooling system performance degradation or failure (see photos: silicon hose and radiator). That’s why vehicle manufacturers prescribe precisely which standards and coolant technologies should be used and caution against mixing different products. NONE FOR ALL Mercedes-Benz, MAN and Scania prescribe coolants using Si-OAT (silicated organic acid technology) for the latest Euro 6 utility vehicles and fill them with the corre- 8
Higher operating temperatures in engines of the Euro 6/ Final Tier 4 generation can degrade unsuitable coolants, resulting in overheating and deposits. Cooling systems equipped with silicone hoses have special coolant requirements; not all coolants are compatible with them. Silicate deposits can be seen on the inside of the hose shown here. sponding products at the factory. MOTOREX COOLANT M4.0 Si-OAT coolant is backwards-compatible and can be used in Mercedes-Benz and MAN vehicles up to Euro 3 and in Scanias up to Euro 4. However, many manufacturers recommend using only one unadulterated product and never mixing coolants that use different technologies. GOOD TO KNOW Many vehicle manufacturers strive to keep their vehicles’ life cycle costs as low as possible. The higher thermal loads of the latest generation of engines (Euro 6/Final Tier 4) mean coolants have to be up to new tasks. Always observe the following rules for coolants: • Always use coolants in accordance with the manufacturer’s specifications • Change coolant regularly (every three or five years) • Always use an unadulterated coolant (never mix different types)! • The same color doesn’t necessarily mean the same product • Be sure coolant hoses are compatible with the coolant type ADVICE ALWAYS INCLUDED MOTOREX carries a wide range of protective coolants, precisely tailored to each generation of engines and with manufacturers’ approvals. Naturally, the requirements for a Euro 6 truck, a tractor, a piece of construction equipment or a passenger car can be quite different. That’s why advisory services for the right, and always the most economical, choice of coolant always involve gathering a certain amount of information (vehicle fleet or machine inventory, manufacturers’ specifications, logistics, etc.). The range of technologies in use makes it impossible to employ a universal coolant for all vehicles in a mixed fleet, making it important always to follow the manufacturer’s specifications. Your MOTOREX partner and the Technical Customer Service will be glad to assist you with any coolant issues. • THREE TECHNOLOGIES In general, today’s coolants are based on three different technologies. Which type of coolant to use and for how long depends on the engine model year and on the manufacturer’s specifications. HOAT technology (Hybrid Organic Acid Technology) Color Usually turquoise, blue or green Special characteristics Contains silicate, compatible with silicone hoses Usage Suitable for older cast iron engines OAT technology (Organic Acid Technology) Color Usually pink or yellow Special characteristics Silicate-free, long change intervals of up to 5 years possible, VCS-compatible (Volvo) Usage For Scania up to Euro 4, newest Final Tier 4 tractor engines Si-OAT technology (Silicated Organic Acid Technology) Color Usually pink Special characteristics Highly resistant to oxidation (cooled exhaust gas recirculation), contains silicate Usage Suitable for Euro 6 from Mercedes-Benz, MAN and Scania, backwards-compatible to Euro 3 (MB and MAN) or Euro 4 (Scania) MOTOREX MAGAZINE 103 I DECEMBER 2014 9
