1997 Nissan Altima Owner's Manual - Page 134

ENGINE COOLING SYSTEM The engine cooling system is filled at the factory with a high-quality, year-round, antifreeze coolant solution. The anti-freeze solution contains rust and corrosion inhibitors, therefore additional cooling system additives are not necessary. CAUTION When adding or replacing coolant, be sure to use only an ethylene glycol anti-freeze with the proper mixture ratio of 50% anti-freeze and 50% distilled water. The use of other types of coolant solutions may damage your cooling system. Outside temperature down to °C −35 °F −30 50% 50% WARNING ● Never remove the radiator cap when the engine is hot. Wait until the engine and radiator cool down. Serious burns could be caused by high pressure fluid escaping from the radiator. See precautions in ''If your vehicle overheats,'' found in the ''In case of emergency'' section. ● The radiator is equipped with a pressure cap. Use a genuine NISSAN cap or its equivalent when replacement is required. DI1347 CHECKING ENGINE COOLANT LEVEL With coolant reservoir Check the coolant level in the reservoir when the engine is cold. If the coolant level is below MIN, add coolant up to the MAX level. If the reservoir is empty, check the coolant level in the radiator when the engine is cold. If there is insufficient coolant in the radiator, fill the radiator with coolant up to the filler opening and also add it to the reservoir up to the MAX level. 7-4 Antifreeze Distilled water