10 Best Antifreeze Coolants 2026 in the United States

The Genuine 00272 SLLC2 Engine Coolant / Antifreeze is a reliable product in the antifreeze-coolant category. This coolant is a single quantity item, weighing 9.34lbs, and includes a bittering agent to prevent accidental ingestion, which is a thoughtful safety feature. The product does not require a core charge, making it straightforward to purchase and use.

Since it is compatible with several vehicle types, it offers good versatility. The long service life is suggested by its good standing in the market since 2012 and its strong sales rank. This coolant is best suited for those looking for a trusted antifreeze option, particularly if they are familiar with the Genuine brand and their vehicle's compatibility with this type of coolant.

The PEAK OET Extended Life Violet 50/50 Prediluted Antifreeze/Coolant is designed especially for European vehicles like Audi, Mercedes, Porsche, and VW that require a silicate-enhanced organic acid technology (Si-OAT) formula. Being 50/50 prediluted means it’s ready to use right out of the bottle, making it very convenient if you need to top off your cooling system without mixing. This product protects your engine by preventing rust and corrosion, which helps keep all cooling system parts in good shape.

One standout feature is its long service life—it’s guaranteed to last up to 150,000 miles or 5 years when used after a full system flush, which is great if you want to avoid frequent coolant changes. It also contains a bittering agent to discourage accidental ingestion, adding a safety aspect. On the downside, this antifreeze is specifically formulated for certain European vehicles, so it might not be the best choice for other car brands or older models.

Also, because it’s pre-mixed, there’s no option to adjust concentration for extreme climates, which could be a limitation if you live somewhere with very harsh winters or summers. If you own a compatible European car and want a coolant that’s easy to use, offers strong protection, and lasts a long time, this PEAK product is a solid option.

The Mopar 10 Year/150,000 Mile Coolant 50/50 Premixed is a reliable antifreeze-coolant that stands out due to its long service life and easy-to-use pre-diluted formula. Being a 50/50 premixed solution, it's convenient for users as it eliminates the need to measure and mix with water. This product is designed for a wide range of vehicles, including Alfa Romeo, Chrysler, Dodge, Jeep, Ram, and Fiat models, making it highly versatile.

With a service life of up to 10 years or 150,000 miles, it offers a long-lasting solution for protecting your engine. The coolant performs well in a wide temperature range from -34°F (-37°C) to 265°F (129°C), ensuring robust performance in various climates. In terms of compatibility, it's formulated to meet ASTM D3306 standards, making it a reliable choice for the specified vehicles. The Mopar coolant also includes additives that help prevent rust and corrosion, enhancing engine longevity.

On the downside, this product is quite specific in its applications and may not be suitable for vehicles outside its compatibility list. Additionally, since it's pre-diluted, you can't adjust the concentration if needed. Despite these minor limitations, the Mopar 10 Year/150,000 Mile Coolant is a highly reliable product reflecting its efficacy and user satisfaction.