Newer coolants use an Organic Acid Technology (OAT) and last up to twice as long as older coolant. In some cases these long-life coolants can last over 5 years or 100,000 miles. Coolant, as it relates to vehicles, is typically a liquid or gas substance used to regulate the temperature of your engine. Liquid coolants are generally half water and half ethylene glycol. Water is used to transfer heat while ethylene glycol is used to lower the bitter point of the liquid. In colder climates, this is extremely difficult. Interestingly enough, this isn't the first time you've heard of ethylene glycol as it is the fundamental ingredient in the prominent term "antifreeze". Keep in mind, you never want to pour antifreeze or water by themselves into your engine system. They need to be combined to create the essential coolant.