Best Car Antifreeze

Buying guide for Best car antifreeze

While car antifreeze may seem secondary to oil and gas when it comes to the fluids you put in your vehicle, it’s a vital element to your vehicle’s operation. This is especially true in northern climates where extreme cold can quickly freeze fluids, resulting in burst hoses and other damage to your engine. A quality antifreeze can also help to protect your engine from corrosion and can help improve your gas mileage.

When shopping for car antifreeze, you will quickly discover a wide variety of brands and types. This may leave you with a number of questions. Do you need premixed antifreeze or a concentrated antifreeze? What are the different colors for? Are additives important? Would a particular antifreeze even work in your vehicle? For these reasons and more, choosing the right antifreeze can be challenging.

In our buying guide, we answer all of these questions to help you find the right antifreeze for your vehicle and environment.

Traditionally (pre-OAT/HOAT), American vehicles used both silicates and phosphates as inhibitors. Japanese cars used phosphates but no silicates, while European cars used silicates but no phosphates.

Key considerations

Premixed vs. concentrated

One of the first choices you will need to weigh is whether a premixed antifreeze or a concentrated antifreeze is right for you.

While it may sound counterintuitive, all antifreeze must be mixed with water before it can be put in your car. Some brands are sold as a concentrate that you mix with water. Others ship as a premix; water has already been added.

Premixed formulas are convenient, and the standard blending ratio — 50/50 water to antifreeze — is recommended for colder climates. Concentrated formulas are made for those who wish to blend their own antifreeze mixtures. For example, in warmer regions where winter temperatures aren’t so extreme, a 70/30 ratio of water to antifreeze often works well and can save you money.

Ethylene glycol vs. propylene glycol

While antifreeze is made largely from glycol (due to its high boiling and low freezing points), glycol is available in two different types: ethylene glycol and propylene glycol.

• Ethylene glycol (EG): First introduced in 1926, ethylene glycol is used in the majority of antifreezes even today. It is also extremely toxic.
• Propylene glycol (PG): The toxicity of ethylene glycol gave rise to the more environmentally friendly propylene glycol. While less common, this glycol is available in some antifreezes that are usually labeled as being less toxic. Note that we don’t say safe, as propylene glycol is still something you don’t want to be drinking. But for those with pets or children, propylene glycol may be a better alternative to ethylene glycol.

Temperature rating

If you live where temperatures can plunge below zero in the winter, you’re going to want an antifreeze that lives up to its name. Antifreezes are rated to a variety of low temperatures that vary by brand or type. Some 50/50 blends are specifically formulated to stay in liquid form at temperatures as low as -50ºF, while most have minimum temperatures closer to -25ºF or -35ºF.

Check the antifreeze container or listing to verify what temperature it is rated for, and buy with your climate in mind.

Longevity

Antifreeze in your vehicle will break down or become contaminated over time. This longevity can vary from brand to brand.

The standard is 5 years per 150,000 miles, but various antifreezes can range from 3 to 10 years and 50,000 to 150,000 miles before you will need to change them. To further complicate the issue, your vehicle will have a maintenance schedule that may specify when antifreeze should be changed.

Using your maintenance schedule and the antifreeze brand recommendations, set up a schedule for when the antifreeze should be flushed from your vehicle and replaced. You should also keep an eye on the antifreeze, testing it for temperature ratings (inexpensive testers are easily found) and visually inspecting it for a muddy consistency that indicates it should be changed.

Is it designed for your vehicle?

Some antifreezes are designed to meet the needs of specific brands of vehicles. Check the container or listing carefully to verify that a particular antifreeze can be used in your brand of vehicle.

Features

Antifreeze colors

One unique aspect of antifreeze is the variety of colors you can find it in. This is more than an aesthetic feature — the coloring here actually signifies different types of antifreeze. The two most common colors are green and orange.

• Green used to be that all you could find, and it is still popular today. Green antifreeze indicates that it is an inorganic additive technology (IAT) blend and contains phosphates or silicates to help protect your engine.
• Orange antifreeze is an organic acid technology (OAT) blend that is designed for newer engines. It does not contain silicates or phosphates and can generally last longer than green/IAT antifreeze in your engine.
   

The third type of antifreeze that is common is a hybrid OAT (HOAT), also known as G-05. It is available in a variety of colors.

Your best bet is to check your owner’s manual to verify what type and color you should be using in your vehicle.

Additives

Around 5% of a typical antifreeze is made up of additives or inhibitors that perform a variety of functions such as fighting corrosion and lubrication. Because these are often proprietary, manufacturers are not required to list them unless they are environmentally harmful. The two primary additives that we’ve mentioned — phosphates and silicates — are used in green antifreeze to protect iron, aluminum, and elements such as water pumps within the cooling system of your engine.

Another widely used additive is bittering agents, which are used to dissuade pets and children from drinking the antifreeze.

Childproof cap

We’ve mentioned antifreeze’s toxicity several times, so this feature should be no surprise. Ensure that whatever antifreeze you buy has an effective childproof cap.

Car antifreeze prices

There’s not a very wide price range involved when you are comparing the majority of antifreezes, which allows you to focus on brand name and antifreeze type.

Inexpensive

Most products start at around $15 per gallon. At lower price points, you will find more general antifreezes, usually with lower longevity and few special additives or features.

Mid-range

In the $20 to $25 per gallon range, you will find antifreezes that can go longer before having to be replaced, in addition to those that are geared towards more extreme temperatures.

Expensive

The most expensive antifreezes are often “high-performing” antifreezes that cost up to $30 per gallon or more. Antifreeze geared towards specific vehicles also falls into this range.

Tips

• Antifreeze or coolant in the original container (i.e. that hasn’t been used in your vehicle) should have an almost indefinite shelf life when stored out of direct sunlight in your garage.
• If antifreezes of different colors are mixed, the best solution is to completely flush the system and refill it with an antifreeze recommended by the manufacturer of your vehicle.
• The various colors associated with antifreeze types are actually all dyes that are added to distinguish between the types. Before the addition of these dyes, all antifreeze types are colorless.
• If you suspect a pet has been poisoned by antifreeze, call the ASPCA’s Animal Poison Control Center hotline at (888) 426-4435.
• If your antifreeze coolant has an oily appearance, it may mean that you have an internal head gasket leak. As this can be a serious problem, you should contact your mechanic immediately for an appointment to isolate the problem.
• When checking your radiator antifreeze or coolant, also do a quick visual inspection of the coolant system hoses to check for any obvious cracks, bulges, or other problems.

Antifreeze was originally designed to overcome the limitations that water faced as a coolant.

FAQ

Q. Can I combine antifreeze colors?

A. While some antifreezes specifically state that they are safe to mix with all colors of antifreeze, this is not always the case. Mixing colors will usually end in one of several ways, none of them beneficial.

At the very least, you can dilute the additives that protect your cooling system. This leaves the additives either less effective or cuts down on the longevity of the antifreeze.

Mixing colors can also create a thick gel, which will flow poorly or not at all through your cooling system, causing the engine to overheat and damaging everything from water pumps and radiators to engine gaskets and heads.

Q. How should I dispose of antifreeze?

A. As all antifreeze is toxic to a certain extent, it should be handled with care when using and discarding it. When filling your radiator, promptly clean up any spills and hose the area down. Cat litter can be used to soak up antifreeze and can then be swept up and thrown away.

To properly dispose of antifreeze, contact your local garage or hazardous waste disposal office to find specific ways to deal with antifreeze in your area.

Q. Do I need to check my coolant level frequently?

A. You should check your coolant level about as often as you clean your radiator — at least once a year. In newer vehicles, you can usually do this without having to open the radiator simply by checking the level in the radiator reserve tank. Add antifreeze — of the correct color — to top up the fluid level to the “full” line on the reserve if necessary.

Be sure that the engine is cold when you check the levels of any fluids.