OAT vs. HOAT Coolant: What Jeep Wrangler Owners Need To Know

Quick Answer: What Is the Difference Between OAT and HOAT Coolant?

OAT and HOAT are two different coolant technologies used in Jeep Wranglers. OAT coolant is used in 2013 and newer models and lasts longer, while HOAT coolant was used in 2012 and older models. Mixing the two can cause engine damage and should be avoided.

As a Jeep Wrangler owner, understanding the differences between OAT and HOAT coolants is crucial for maintaining your vehicle's cooling system. Let me show you what these coolants are and why you need to be cautious when adding new coolant to your Jeep.

Prepping my Jeep Wrangler for
coolant maintenance with
Mopar OAT antifreeze. 

What Is OAT Coolant?

OAT (Organic Additive Technology) coolant is used in Jeep Wranglers from 2013 and newer.

• Uses organic acid-based corrosion inhibitors

• Lasts up to 10 years or 150,000 miles

• Typically purple in color for Jeep vehicles (see note below)

 What Is HOAT Coolant?

HOAT (Hybrid Organic Additive Technology) coolant was used in Jeep Wranglers 2012 and older.

• Combines organic and inorganic corrosion inhibitors

• Lasts about 5 years or 100,000 miles

• Typically orange or pink in color (see note below)

Using Mopar OAT antifreeze during
my Jeep Wrangler coolant change.

⚠️ Why You Should Never Mix OAT and HOAT Coolant

Mixing OAT and HOAT coolants can lead to serious problems:

Chemical Reaction: When mixed, these coolants can cause a chemical reaction that may lead to the coolant gelling.

Corrosion: Using the wrong coolant can accelerate corrosion within the engine and cooling system.  

Engine Damage: Improper coolant use can potentially cause significant engine damage, leading to costly repairs.

Reduced Effectiveness: Mixing coolants can diminish their protective properties, leaving your engine vulnerable to overheating and corrosion.

Jeep Momma Tip: If you feel you are losing coolant or smell that "anti-freeze smell" check your radiator for leaks. Some Jeep Wrangler model years are known for radiator leaks. 

Best Practices for Jeep Wrangler Coolant Maintenance

To ensure the longevity of your Jeep Wrangler's cooling system:

Know Your Model Year: Jeeps from 2013 onwards use OAT coolant, while earlier models use HOAT.

Use the Correct Coolant: Always use the manufacturer-recommended coolant for your specific Jeep model and year.

Avoid Universal Coolants: While some brands claim to be compatible with all coolant types, it's best to stick with the specific coolant recommended by Jeep.

Flush Before Changing: If you're switching coolant types, perform a complete system flush to avoid mixing.

Emergency Situations: If you must use a different coolant in an emergency, flush the system and replace it with the correct coolant as soon as possible.

Regular Maintenance: Keep an eye on your coolant levels and condition, and follow the recommended service intervals.

How to Identify the Coolant in Your Jeep Wrangler

Check the color of the coolant:

OAT (Organic Additive Technology) coolant used in 2013 and newer Wranglers is typically purple in color.

HOAT (Hybrid Organic Additive Technology) coolant used in 2012 and older Wranglers is usually orange or pink.

NOTE: Be careful when trying to pin down the exact color. One person's pink is another person's purple. Also understand the color looks different when looking inside the radiator. 

Look at the coolant reservoir:

For newer models (2013+), the coolant reservoir is a pressurized tank with a black cap.

Older models (2012 and earlier) may have a non-pressurized reservoir.

Check your Wrangler's model year:

2013 and newer Wranglers use OAT coolant.

2012 and older Wranglers use HOAT coolant.

Examine the coolant bottle if you have it:

OAT coolant is typically rated for 10 years or 150,000 miles.

HOAT coolant is usually rated for 5 years or 100,000 miles.

If you're still unsure, it's best to consult your Jeep's manual or contact a Jeep dealership for confirmation. Remember, it's crucial not to mix OAT and HOAT coolants, as this can cause a chemical reaction that may damage your engine

By understanding the differences between OAT and HOAT coolants and following these guidelines, you can help ensure your Jeep Wrangler's cooling system remains in top condition, potentially saving you from costly repairs down the road.

For more essential Jeep Wrangler maintenance tips, visit my Jeep Wrangler Maintenance Basics.

❓ Frequently Asked Questions About OAT vs. HOAT Coolant

Can I mix OAT and HOAT coolant in an emergency?
Mixing is not recommended. If it happens in an emergency, flush the system and replace with the correct coolant as soon as possible.

Can I use universal coolant in my Jeep Wrangler?
Universal coolants claim compatibility, but Jeep recommends using the specific coolant type for your model year.

How often should Jeep Wrangler coolant be changed?
OAT coolant typically lasts up to 10 years or 150,000 miles, while HOAT coolant should be changed about every 5 years or 100,000 miles.