Can you mix different types of coolant in your car? Complete Guide

Are you confused about mixing different types of coolant in your car? Don’t worry, you are not alone!

This guide will answer all your questions and ensure that you drive safe with the right type of coolant. You’ll learn how to mix different coolants, what to consider when mixing them, and how to identify the best type of coolant for your vehicle.

Get ready to drive safely and confidently!


The cooling system of a vehicle is an extremely important component. It circulates coolant fluid through the engine, radiator and other heater components in order to dissipate heat. While most modern cars are designed to perform well with just one type of coolant, some car models require different types of coolant for different temperature experienced in colder or hotter climates. If you’re not sure what kind of coolant your car needs, it’s important to find out before you mix the wrong type and cause damage to the engine.

To help you understand everything about coolants and mixing different types, this guide will walk you through:

  • What is Coolant?
  • Why Should You Use The Right Type Of Coolant?
  • What’s The Difference Between Types Of Coolants?
  • Can You Mix Different Types Of Coolants?
  • What Are The Dangers Of Mixing Different Types Of Coolants?

By the end of this guide, you will have a better understanding of the differences between various types of coolants and the risks involved with using incompatible fluids.

Definition of engine coolant

Engine coolant, or antifreeze, is a liquid used to regulate the temperature of an engine and protect it from freezing or overheating. It also keeps the engine running at an optimal temperature and helps with corrosion control. There are a variety of different types of coolant on the market all intended for use in different engines, and it’s important to understand which type is best for your vehicle. Coolants are usually a mixture of ethylene glycol (ethylene oxide) and water but can contain additional ingredients to improve their performance in certain applications. Different types may be labeled differently but all share the same function. Some common categories including antifreeze/coolant, silicate blended antifreeze/coolant, organic acid based inhibitors (OATs), hybrid organic acid technology (HOATs) and nitrate-free formulations.

It’s important to note the differences between these categories so you can make the best decision when it comes to selecting a coolant for your car. Not all coolants are compatible with each other, so you need to determine your car’s needs before adding any new product. Mixing any chemicals before consulting with an expert or referring to relevant manual will likely lead to poor performance as well as potential damage down the line.

Overview of mixing different types of coolant

Mixing coolants that contain different inhibitors, such as organic acid, inorganic acid, or silicate based coolants, can have a negative impact on your vehicle’s cooling system. Introducing different types of coolants can cause accelerated corrosion due to reaction between the inhibitors and components of the cooling system. It is, therefore, important to know what type of fluid is currently in your vehicle, as well as the type of fluid being added.

Most importantly, one must always maintain a minimum concentration level for the coolant chosen. Coolant that has been properly maintained will provide better performance in deterring corrosion and protecting other cooling system components than coolant that is simply topped up without any further consideration. Most qualified mechanics suggest flushing your cooling system at regular intervals specified by vehicle manufacturers to ensure that residual contamination is removed from the system; this applies whether or not you mix types of coolant or not.

Types of Engine Coolant

Engine coolants come in various types, each designed to provide specific performance benefits as related to protection and other characteristics. Automotive products are commonly divided into two categories: ethylene glycol (EG) and propylene glycol (PG). Ethylene Glycol can be further broken down into traditional and extended life coolants.

Traditional Ethylene Glycol (EG) Coolant: Traditional EG coolants are the mostly widely available automotive coolant, and often a less expensive option. These products typically contain silicates buffered by borate or phosphate that offer protection against corrosion and cavitations over a 1-2 year period. Antifreeze/Coolant products sold for consumer use also generally fall into this category.

Extended Life Ethylene Glycol Type Coolant: These type of antifreeze/coolants contain Organic Acid Technology (OAT) inhibitors, like mono-octyl phosphate or sebacate that can provide up to 5 years or 150,000 km / 100,000 miles service life – along with proper flushes as recommended by the vehicle manufacturers maintenance schedule – depending on the type of glycol used in their formulation. A few examples of OAT include G11 (Honda brand), Dexcool® (GM brand), Zerex Supersweet® (Valvoline brand), VW G12+ Coolant, Nisan Long Life Blue Coolant $01 QX1-K2QAB1″).

Propylene Glycol Type Coolants: Propylene Glycool based antifreeze/coolants do not contain silicates are phosphate free formulations that were developed primarily for passenger cars with aluminum radiators containing plastic components near cylinder head(s). The inhibitors contained in PG formulations are phosphate free offering better protection than conventional ethylene glycol type production when used in engines with aluminum components . They also may offer better compatibility with seal materials in certain vehicles such as BMW Vw, Porsche etc..

Inorganic Acid Technology (IAT)

Inorganic acid technology (IAT) coolants are typically used in older car, truck, and other vehicle fleet models. This type of coolant was commonly referred to as “green” or “silicate-based,” as it contains silicates for corrosion protection. However, IAT coolants are limited to corrosion protection measures and have lower freeze point ratings –– which makes them a less desirable option for most modern vehicles.

It is important to note that this type of coolant should never be mixed with any other form of coolant as it can cause severe system damage. If you do decide to use IAT coolant in your vehicle, always check your manufacturer’s recommendation on the proper mixture and change intervals.

Can You Mix Coolant? What You Should Know! ❤️ Everything You Need To Know!  ❤️

Organic Acid Technology (OAT)

Organic Acid Technology (OAT) coolants are some of the newest designs for automotive cooling systems. OAT coolants are extremely effective corrosion inhibitors which do not contain silicates, borates and phosphates found in other traditional coolant.

In addition, they feature organic acids including sebacate, Glysantin®, and other chemical compounds that act to protect water pump gaskets, sealants, linings and internal components until the recommended testing interval. They also offer decreased system maintenance requirements since they do not require pressure testing as frequently as silicate coolants and they can be used without changing out the thermostat on modern cars and light trucks.

Lastly, OAT coolant is usually brown or pink in color to set it apart from other types described here.

Can Different Types of Coolant be Mixed?

Yes, it is possible to mix different types of coolant, but it’s important to consider your engine type before doing so. In most cases, you should stick with a single type of coolant in order to make sure your car’s cooling system works properly. However, if you find yourself short on one type of coolant and need to top up the system in an emergency situation, a blend of two different types is generally acceptable.

As a general rule of thumb, it’s best not to mix green and orange antifreeze. Green antifreeze is made with silicates (inorganic) and protects against corrosion whereas orange antifreeze is made with organic or phosphate compounds that are designed for aluminum engines. When the two are mixed together, this can cause problems because the components are incompatible and over time can lead to sludge forming within the pipes and radiators in your vehicle.

However, blends between different colors of organic or ethylene glycol based antifreese can usually be safely mixed as long as it’s not done on an ongoing basis. The same goes for any mixture between new synthetic formulas such as DexCool (orange/yellow) and non-syntheic (green). Keep in mind that because mixing two different types isn’t ideal, you’ll want to plan ahead by stabilizing its pH level when adding more coolant at a later date if needed so that there isn’t drastic variation between batches which could damage components within your cooling system.

Mixing Different Types of Coolant


Mixing different types of coolant for use in your vehicle can lead to some serious issues. Different types of coolant are formulated with unique chemical makeups that are designed to interact with the metal components and gaskets inside your engine in a specific manner. In general, coolants may be either organic acid–based or silicate-free.

Organic Acid–Based Coolant: This is the most common type of coolant found in vehicles, and often it is referred to as “green” since it is typically a bright shade of green in color. Organic acid–based coolants contain anti-corrosive elements such as phosphates, zinc, and silicates that help protect radiators, cylinders, and other metal components from corrosion by providing a barrier between them and the water they are mixed with.

Silicate-Free Coolant: This type of coolant is formulated without any silicates present in its composition. As such, it typically has far fewer anti-corrosion properties than organic acid–based coolants; however, this lower level of protection also means that less build up occurs on cooling system parts over time. This can reduce maintenance time while still providing adequate protection to most engines.

When mixing different types of coolant together you could be creating a mixture that does not perform optimally for your engine, leading to further problems such as clogged radiators or leaking gaskets due to an improper chemical balance. To maximize performance and engine life we recommend sticking with the same type of product that was originally added to the vehicle when performing maintenance on your car’s cooling system.

Effects of Mixing Different Types of Coolant

Mixing different types of coolant in the system can cause a range of issues. Most common among them is a phenomenon known as ‘gumming’, where the different types of coolant combine to form deposits in the cooling system that could lead to a significant reduction in circulation and thus, cooling efficiency. Furthermore, conflicting pH levels between different coolants can also cause similar deposits. Therefore, it is always advised against mixing two different types of coolant in an attempt to increase a car’s longevity or performance.

Aside from gumming, mixing different types of coolant has been known to cause antifreeze odors inside the cabin. Moreover, the concoction created through mixing together two such indistinguishable liquids could be toxic and poisonous for human consumption if accidentally ingested. Therefore, it is advised that you keep containers used for housing any fluid away from your children and pets so that no accidents occur when dealing with these substances.

Coolant Basics, Can You Mix Different Types?


In conclusion, mixing different types of coolant in your car can have many potential issues — from potential damage to your car’s engine and cooling system to decreased performance. While it can be done in certain situations, it should not be taken lightly nor done without fully understanding the implications.

The best advice is to try and identify the coolant currently used in your car and adhere to that brand if possible. If you must mix different coolants, always use a compatible one with the recommendation of a professional mechanic or service advisor. Most of all, ensure a regular maintenance program utilizing fresh coolant is observed so you can keep your engine running strong for years to come!

Recap of mixing different types of coolant

Understanding the basics of mixing different types of coolant will help you in determining which type to use for your vehicle. In most cases, using a coolant that is recommended by the car’s manufacturer is the best choice. However, there are times when mixing different types of coolant could be beneficial.

When adding new coolant to a car’s radiator, it may be necessary to mix the fluid with an already-existing liquid in order to achieve specific levels of protection against corrosion and freezing. Additionally, if a vehicle isn’t able to use the type of coolant recommended by its manufacturer, then mixing two compatible fluids may be necessary.

Before attempting to mix two different types of coolants, it’s important to review information provided by both versions’ manufacturers as each one can provide significantly different results when mixed with another type but not enough to cause any damage or decreased performance from your car. The following components should also be considered:

  • Compatibility: Is each type compatible with one another?
  • Performance: How does each affect the performance of your car?
  • Safety: Are either unsafe for drivers or passengers?

Importance of using the correct type of coolant

When it comes to engine coolants, using the wrong type can have severe consequences that could lead to expensive damage and repairs. It is therefore essential to use the correct type of coolant for your vehicle and, if necessary, top up with the same brand or equivalent.

Generally speaking, all types of coolants are based on either a glycol or an organic acid base. Glycol-based coolants are broken into ethylene glycol (EG) and propylene glycol (PG). Each has advantages, such as engine protection in extreme temperatures and corrosion prevention. However, they can also react with each other, often producing a sludge-like substance. This sludge is highly damaging to your car’s cooling system and can be very difficult to clean out of the system.

EG-based products have been available since 1937 and have been used in almost every car make and model ever since then. PG-based coolant was introduced in 1995 but its use was soon after discontinued due to health concerns associated with its toxicity when used as antifreeze. These days there are many different types of engine coolants so it is important that you use the correct type for you car’s needs. The manufacturer’s recommended specification is always best but good equivalents can be found on the market for less cost.

Importance of maintaining the correct ratio of coolant and water.

It is important to always maintain the correct ratio of coolant and water in your car’s cooling system. Mixing coolants can create dangerous chemical reactions which can lead to engine damage that may be irreversible. It is also important to make sure that the coolant you use is compatible with the materials and technology used in your vehicle’s cooling system, as mixing incompatible liquids may also cause damage.

In general, it is best to stick to either one type of coolant (typically an OAT coolant) or mix coolants with similar compositions (such as silicates, 2-EHA, or nitrate-based). Always check your owner’s manual for recommendations on necessary maintenance, such as changing and flushing your vehicle’s cooling system regularly.

Additionally, measurements designed for passenger cars should not be used for heavy-duty trucks; instead, consult a professional mechanic or service center if you have difficulty determining what type of coolant and amounts works best for your vehicle.

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