2001 Nissan Frontier Owner's Manual - Page 202

ENGINE COOLING SYSTEM The engine cooling system is filled at the factory with a high-quality, year-round, genuine NISSAN anti-freeze coolant solution. The anti-freeze solution contains rust and corrosion inhibitors, therefore additional engine 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% Genuine Nissan Anti-freeze coolant or equivalent and 50% demineralized or distilled water. The use of other types of coolant solutions may damage the engine cooling system. Genuine Nissan Antifreeze coolant or equivalent 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 of this manual. ● The radiator is equipped with a pressure type radiator cap. To prevent engine damage, use only a genuine NISSAN radiator cap. ADI1026 CHECKING ENGINE COOLANT LEVEL Check the coolant level in the reservoir tank when the engine is cold. If the coolant level is below the MIN level, add coolant to the MAX level. If the reservoir tank 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 tank up to the MAX level. Outside temperature down to Demineralized or distilled water °C −35 °F −30 50% 8-6 Do-it-yourself