Does Prestone Antifreeze Contain Silicates?

Does Prestone Antifreeze Contain Silicates?

Seems like almost everyone has had one of those yellow jugs in the trunk of their cars just in case steam or something green starts to ooze out from under the car. It felt safe to drive a car that overheats as long as there was a jug of Prestone antifreeze in the trunk. But is Prestone safe to use in your car? Even if you’ve never had to refill your radiator, read on to find out about Prestone and their many antifreeze products.

Who is Prestone?

Prestone has produced coolant/antifreeze since 1927. Some would even say that Prestone pioneered antifreeze. The coolant (view on Amazon) is a mix of ethylene glycol antifreeze and water that are designed to remove heat from the engine. The goal has been to protect vehicles from the harsh effects of time and environmental conditions. In 1944, Prestone antifreeze was used to keep the US military vehicles cool in extreme conditions. In 1961, Prestone introduced Long Life Coolant which was designed to specially cool the metals under the hood. The company also pioneered nonflammable antifreeze. As the design of the automobile began to evolve to more sophisticated design, antifreeze has also evolved. In 1977, Super Fluch was added to the antifreeze to prevent rust and scale. By 2004, Prestone had introduced an antifreeze that would work in any car or light-duty truck.

What is Antifreeze?

No one wants their engine to freeze or overheat. Thus, internal combustion engines have cooling systems with a mix of ethylene glycol antifreeze and water that is designed to prevent freezing, overheating, and buildup. There are passages in the engine block and also in the engine heads. A water pump circulates the antifreeze through those passages, which is moved around by hoses and cooled in the radiator. The antifreeze then travels through the parts of the engine, absorbing the heat. The heated coolant travels through rubber hoses to the radiator. Natural air coming in from the grill cools the antifreeze as it passes through the radiator. The coolant then returns back to the engine and the process starts all over again.

The primary job of antifreeze is to keep things cool. The engine requires consistent flows of coolant. If temperatures under the hood get hot enough, the coolant will start to evaporate. The engine gets extremely hot and forces the liquid out. When the coolant has air, it does not absorb heat from the engine the same way. The engine may overheat due to a lack of antifreeze or from antifreeze leaks or not circulating. The passageways could be blocked, or there simply is not enough coolant running through the system to keep everything cool. When the vehicle is serviced, the technician will check the coolant levels in the radiator and reservoir. Adding coolant only becomes necessary when there are problems in the cooling system that can cause a loss of coolant.

What is Silica?

Silica, or silica dioxide, is a chemical compound made up of silicon, one or more metals, and oxygen. The chemical is widely classified as a salt of various types of silicic acids. Silica is one of the two most abundant elements found in the Earth’s crust. In fact, 59% of the Earth’s crust is made of silica and it is also abundant in beach sand. The compound is known in chemistry terms as SiO2. Silica comes in three main forms: cristobalite, quartz, and tridymite.

Silica is not only very abundant in the earth, it also has many uses. Silica sand is often used in construction of buildings and roads. This form is either concrete, Portland cement, sandstone, or mortar. Silica is also often used to grind and polish glass and stones, the manufacture of glass, silicon carbide, ceramics, and ferrosilion. It is known for its use as a refractory material, and as gemstone. Silica gel is used as a desiccant that removes moisture.

Does Prestone Antifreeze Contain Silica?

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Many assume that the new Prestone products are not made with silicates. Although Prestone is a household name for coolants, many may wonder if Prestone antifreeze products contain silica. The answer is yes and no. As the coolant industry began to shy away from adding silica to antifreeze, especially in Europe and Japan, Prestone began making products to keep up with the trend. So, the answer is, Prestone has a large variety of antifreeze products and some contain silica while others don’t.

Obviously, the Prestone AF3300 Prime Green 50/50 Antifreeze and the Prestone AF3200 Prime Antifreeze/Coolant Conventional Green Low Silicate Formulation contain silicates. The bottle label claims that the silica levels are very low. Yet, the product does contain silicates. The Prestone Regular, or 50/50 is an OAT antifreeze that is silicate free. The silicates in this product are replaced by phosphates. In order to tell if the Prestone antifreeze contains silicates, it’s best to read the label.

Silica in Antifreeze

There are three primary forms of antifreeze, or ethylene glycol: silica-based or green antifreeze, organic acid or OATs, and hybrid coolants which are a combination of organic acid mixed with silicates. You’ve probably seen a green coolant leak where the green liquid puddles under the car. However, green antifreeze is slowly becoming a thing of the past. That’s because green coolant is comprised of ethylene glycol, green dye, and silicates. The maintenance cycle for green antifreeze is longer than that of newer formulas. Newer formulas of antifreeze come in different colors and contain less silicates. Historically, coolants in the US have been green. Yet, some may be amber, yellow, red, orange, or the conventional green.

Silica in the automobile provides the metal parts, including aluminum, a high level protection against corrosion. The silicates charge up the cooling system for about 2 years of protection. Most hybrid coolants contain a combination of inorganic inhibitors and carboxylates such as phosphates to provide the protection. After 2 years, the silica-based antifreeze should be replaced as silica drop out occurs. This means that the silica has disappeared from the antifreeze. If it is not replaced, buildup occurs in the radiator and cause overheating problems and low performance. The metals are no longer protected and begin to deteriorate.

When you drive, the environment under your hood is aggressive and hot. When the car is on the move, natural air presses in and cools the engines. Yet, sometimes the natural air is not enough. When the engine really heats up, the coolant volume expands inside the hoses and the engine. Heavy duty vehicles in particular depend heavily on the silicates for protection. These vehicles can be recharged without having to flush the coolant. In heavy duty diesel engines, one third of the total energy that is generated is used to push the vehicle forward. One third of the energy is removed as heat by the exhaust system. The last third of heat energy is removed by the coolant. Therefore, the antifreeze used in heavy duty vehicles has a big job.

The coolant can come in different colors depending on the manufacturer. So, you may ask, “What is the difference between antifreeze brands?”. One type of antifreeze is differentiated from another by the type of additives it contains. Corrosion inhibitors, dyes, and antifoams are some of the types of additives found in antifreeze. There are several types of high and low quality coolants of different colors on the aftermarkets. However, the color of the coolant is not an indicator of quality. The vehicle manufacturer will likely recommend the best coolant for their vehicles.

Do You Really Need Antifreeze?

Yes, of course you may be saying water is a natural coolant, and besides, the coolant has water in it. Those things are true, but antifreeze stretches the freezing and boiling properties of water to accommodate the high operating temperatures under your hood. Yet, water freezes at 32 degrees and boils at around 212 degrees Fahrenheit. When you use coolant, the boiling point is 264 degrees Fahrenheit and the freezing point is -34 degrees. Antifreeze provides a protective coating on the radiator and can withstand higher and lower temperatures much better than water. Water can do the job of transferring heat; however, the glycol provides the protection against freezing. Also, tap water leaves mineral deposits in the radiator which build up and cause corrosion. The radiator is rendered less efficient and its life cycle is decreased.

Hard water has been a problem noted in the US and in Europe. The hard water has harmful minerals, such as calcium and magnesium, which react with phosphate inhibitors and cause scale formations on the engine surfaces when the engine is hot. This problem is so severe that it has forced some antifreeze producers to leave out the phosphates. To replace the phosphates, European manufacturers started to use inorganic oxides to include silicates or carboxylate inhibitors. The carboxylates and the silica add protection by mixing with metal corrosion. This mix of carboxylates and silica are referred to as the hybrid technology due to the mix with organic technology.

Your Need to Know This About Your Coolant

Your vehicle’s systems are able to cool down because of the coolant. If you want to make sure that the cooling system is working properly, you need to make sure that the coolant in there is functioning properly.

If you want to avoid coolant problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.

A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.

Should Antifreeze Contain Silica?

Since silicates help to protect against freezing and buildup, why is their use in antifreeze so controversial? Despite their important function, silicates are regarded as abrasive on the cooling system. They also contribute to failure of water pump seals. The water pump circulates the coolant through the passages, which is moved around by hoses and cooled in the radiator. Some Asian regions have banned antifreeze with silicates due to the damage to the water pump seal.

Maintenance Makes the Difference

Whether you use antifreeze with silica or antifreeze without, it is still important to maintain regular maintenance on your cooling system. When the cooling system in the vehicle has not been serviced or flushed in a while, the old fluid sits and accumulates debris or sediment and even rust that blocks the core or grill over time. The cooling fins in the radiator corrode and coolant leaks will occur.

You can check the coolant level in your radiator yourself by removing the radiator cap. You must make sure the system has cooled down before removing the cap or you may get burned. Once the system has cooled, remove the radiator cap and check the coolant level. If more coolant is required, use proper mix of antifreeze and distilled water to refill the radiator. Keep a container of coolant without silicas and a funnel in your trunk. The next time your car overheats or you see steam coming from the hood, you’ll have the coolant to use instead of just water. In order to keep your car on the road running smoothly for the long run, you can take your car to a car garage and get professional help. They will know how to flush the system, replace the coolant, or service your cooling system

Job Guthiri is a freelance writer with 3 years of experience writing for Motorsrun and other established automobile outlets. His focus and key interests are Tacomas and maintenance. Read our Editorial Guidlines and Fact Checking process.