2010 Chevrolet Cobalt Owner's Manual - Page 302

... Protects against rust and corrosion. Will not damage aluminum parts. Helps keep the proper engine temperature. Checking Coolant The vehicle must be on a level surface when checking the coolant level. Notice: If an improper coolant mixture is used, the engine could overheat and be badly damaged. The repair cost would not be covered by the vehicle warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core, and other parts. Notice: If extra inhibitors and/or additives are used in the vehicle's cooling system, the vehicle could be damaged. Use only the proper mixture of the engine coolant listed in this manual for the cooling system. See Recommended Fluids and Lubricants on page 7‑11 for more information. The coolant surge tank is located in the engine compartment on the driver's side of the vehicle. See Engine Compartment Overview on page 6‑14 for more information on location. 6-30