It may be hard to believe, but antifreeze has been around long before the automobile. In the mid-19th century, it was used in dynamite. Early engine designers tried other means of cooling before antifreeze gained a foothold. It came to prominence during World War I when it was used in tanks and vehicles to prevent them from freezing in the battlefield.
Of course, chemistry has changed and engine designs are not the same as they were a century ago. Today’s modern engines put an even greater emphasis on proper cooling, so it’s important your shop can answer all of your customers’ questions about components and system operation.
Water gives the antifreeze more surface area to transfer heat to the radiator but of course water alone can’t do the whole job. Antifreeze lowers the freezing point of a water-based liquid and increases its boiling point, dependent on the concentration of the dissolved substance. An antifreeze/water mix is used to achieve freezing-point depression for cold environments and produces boiling-point elevation for higher-coolant temperatures.
Different types of coolants cover a range of applications from diesel to domestic, Asian and European vehicles. Each one is formulated to a specific manufacturer’s specifications to keep their engines at an optimal temperature. But, changes to the old one-size-fits-all formula have led to confusion for consumers and even some technicians.
The most common variety of antifreeze is an Inorganic Additive Technology (IAT) formula. This traditional-style green coolant, which has been in use forever, provides corrosion protection as well as lubrication to the water pump. IAT coolants contain either ethylene glycol or propylene glycol with silicate or phosphate additives to increase its compatibility with metal cooling-system components. The generally recommended replacement interval is once a year. Most consumers won’t replace their coolant that often, so new long-life formulations were introduced.
Antifreeze with a long service life is based on Organic Acid Technology (OAT), and each manufacturer has its own blend of additives. However, the majority of the products are typically ethylene glycol-based without any silicates, phosphates, borates, nitrites or amines. It protects metals in the coolant system against rust and corrosion and provides high-temperature aluminum protection. It is fully compatible with other OAT coolants and is recommended for use in newer-model vehicles. Most Extended-Life Coolant (ELC) offers up to a five-year or 150,000-mile service life protection when properly diluted and added as an initial fill.
For best results, ELC should never be mixed with IAT coolants that contain high pH, phosphate, borate or silicate. ELC has an orange color to help differentiate it from traditional “green” coolant (although it is not always green). Mixing conventional coolants with an ELC can reduce the anticipated lifetime of the combined fluids, but it won’t be detrimental to the engine.
If your customers are using IAT coolants, a cooling-system flush and replacement is recommended every one to two years. While extended-life coolant can last up to five years, it’s best to test whether the antifreeze is still active with an antifreeze tester. Antifreeze can break down over time, especially IAT and some hybrid OAT solutions where the additives drop out and therefore don’t provide enough corrosion protection. Contaminated coolant is at a higher risk of boiling over or freezing sooner.
Your customers should use the same type of coolant according to the vehicle manufacturer’s recommendations. It won’t hurt to have a different brand or type, but the effectiveness of each coolant type’s additive package may be compromised depending on their specifications. In general, if they’re mixing coolants, the recommended coolant-change interval will be for the shorter-life coolant.
Maintaining proper mixture and fluid levels ensures corrosion inhibitors are able to protect the engine. Most OEMs create cooling systems to operate with the optimal level of antifreeze. A system that’s always low on coolant creates a corrosive environment.
The water-to-antifreeze ratio is critical, which is why there are so many pre-mixed products available. All pre-mixed coolants are produced with distilled water, so there are no concerns with mineral deposits. If concentrate is used when refilling or topping off any cooling system, it should be mixed with distilled water – not tap or filtered water.
The options your customers face may seem overwhelming – as a professional organizaion your team can ease those concerns.
Because a third of the energy an engine produces becomes heat, the fluid used to transfer it out of the block is as important as what’s put in the gas tank.
