2013 Hyundai Sonata Owner's Manual - Page 340

Maintenance OYF079005N Check the condition and connections of all cooling system hoses and heater hoses. Replace any swollen or deteriorated hoses. The coolant level should be filled between F and L marks on the side of the coolant reservoir when the engine is cool. If the coolant level is low, add enough specified coolant to provide protection against freezing and corrosion. Bring the level to F, but do not overfill. If frequent additions are required, see an authorized HYUNDAI dealer for a cooling system inspection. Recommended engine coolant • When adding coolant, use only deionized water or soft water for your vehicle and never mix hard water in the coolant filled at the factory. An improper coolant mixture can result in serious malfunction or engine damage. • The engine in your vehicle has aluminum engine parts and must be protected by an ethylene-glycol-based coolant to prevent corrosion and freezing. • DO NOT USE alcohol or methanol coolant or mix them with the specified coolant. • Do not use a solution that contains more than 60% antifreeze or less than 35% antifreeze, which would reduce the effectiveness of the solution. For mixture percentage, refer to the following table. Mixture Percentage (volume) Ambient Temperature Antifreeze 5°F (-15°C) -13°F (-25°C) -31°F (-35°C) -49°F (-45°C) 35 40 50 60 Water 65 60 50 40 OYF079006-1 WARNING Radiator cap Do not remove the radiator cap when the engine and radiator are hot. Scalding hot coolant and steam may blow out under pressure causing serious injury. 7 25