There are several types of antifreeze, classified as organic or inorganic , by color , and by concentration . In addition, there are different types of antifreeze: G12, G12+, G13, and the older G11 . We'll tell you everything you need to know about them and whether or not they can be mixed.
Types of antifreeze: organic and inorganic
The first classification of antifreeze is based on its composition. Their functions are the same, but they are very different liquids in terms of both their components and their capabilities.
- Organic Antifreeze: Also called Organic Accident Technology (OAT). It has more durability, it can have a lower freezing point in the more concentrated versions (50%), it has better protection of some modern vehicle materials and the most ecological.
- inorganic antifreeze: also called Inorganic Accident Technology (IAT). It lasts less, its more concentrated versions do not reach a freezing point as low as the organic one, its anticorrosive is more typical of old vehicles and the least ecological
- hybrid antifreeze: or Hybrid Organic Accident Technology (HOAT). They have properties of durability, protection and resistance to freezing similar to organic ones. They are used in some European and American engines.
Mix organic and inorganic antifreeze?
You should not mix organic antifreeze with inorganic or hybrid antifreeze. The base of most organic and inorganic antifreezes is the same, ethylene glycol, but their anti-corrosion components are incompatible. They can even react with each other, canceling out their properties and causing problems in the cooling system.
This is because they are designed to protect different materials from galvanic corrosion . If different metals are in contact within the same conductive liquid, the exchange of electrons will create oxidation that deteriorates them. It's not an absolute rule, but organic antifreezes protect the metals used in modern engines, while inorganic antifreezes protect those in older engines.
Antifreeze yellow, blue, green, pink...
There is no consensus among brands regarding colors . Some use them to differentiate the concentration level, others whether they are organic or inorganic, and still others for the type of vehicle.
For example, Motul Organic Pink and Motul Organic Yellow have the same 50% concentration and identical temperature resistance: from -35º to 145º. However, the former is indicated for cars and transport vehicles, while the latter is also suitable for motorcycles.
In the case of Repsol antifreeze , the colors are used differently:
- Organic: the Repsol of 30% Yellow and the Repsol of 50% Pink
- Inorganic: Repsol Green and Repsol Blue
Mix antifreeze from different brands?
If you've already used a particular brand of antifreeze, it's best to stick with that brand. Mixing different brands isn't recommended unless you're absolutely certain they have the exact same components . Using different concentrations of the same antifreeze won't cause any problems. Mixing equal parts of a 30% and a 50% antifreeze will result in a 40% solution, but since they're from the same manufacturer and are the same type, it won't cause any issues.
Exception : If the antifreeze is G11, G12, or G13, you can mix different brands without problems. Just make sure they are the same type: G12 with G12, G13 with G13, etc. Different types can only be mixed as explained below.
Mix antifreeze of different colors?
You can mix antifreeze of different colors as long as they are the same type . That is, if the color only indicates the antifreeze concentration, there won't be any problems. However, if the color of the brand you have in mind indicates that it's inorganic, while you need organic, you shouldn't mix them. It's also not recommended to mix antifreeze of different colors that indicate they are for different vehicles.
Antifreeze G12, G12+, G12++, G13 and the old G11
These antifreezes are organic and are used by some brands. They are liquids with specific material protection properties. Therefore, if your car requires this type of fluid, it's best not to use any other. If this is the case, you won't have any trouble knowing because manufacturers take care to include it in the expansion tank , a visible location whenever you check the level or change the antifreeze.
These are antifreezes that have evolved over the years . G11 was an antifreeze that began to be used in 1994, G12 and G12+ in 1996, G12++ in 2005, and G13 in 2008. Although they are of the same organic type, it is best not to mix them if you are unsure which are compatible. We will discuss this in the next section.
Can G11, G12, G12+, G12++ and G13 be mixed?
Antifreezes G11, G12, G12+, G12++, and G13 can be mixed, but some cannot . Although they are evolutions of each other, they do not have the same components, so mixing them can cause deterioration or, at the very least, a loss of anti-corrosive properties. The following table shows which ones can be mixed:
| G11 | G12 | G12 + | G12 ++ | G13 | |
|---|---|---|---|---|---|
| G11 | G12 | G12 + | G12 ++ | G13 | |
| G11 | Yes | No | * | * | * |
| G12 | No | Yes | * | * | * |
| G12 + | * | * | Yes | * | * |
| G12 ++ | * | * | * | Yes | Yes |
| G13 | * | * | * | Yes | Yes |
*: Loses anti-corrosion properties
Types of antifreeze according to concentration
The higher the concentration of antifreeze, the lower the temperatures it can withstand without freezing. However, what not everyone considers is that a higher concentration also allows it to withstand higher temperatures without boiling . The most common concentrations are:
- 10 %: withstands temperatures down to -4ºC
- 20 %: withstands temperatures down to -9ºC
- 30 %: withstands temperatures between -16ºC and 18ºC
- 50 %: withstands temperatures between -35ºC and -37ºC
- Pure: It is designed to be mixed with water at a concentration of 50% or less, depending on the needs.
The maximum temperatures they can withstand without boiling also depend on other additives, so they vary considerably between brands. For example, Motul's 50% organic product can withstand up to 145ºC according to the manufacturer, while Tamar 's product can withstand up to 132ºC with the same concentration.
Mix antifreeze of different concentrations?
It can be done without any problem . Just keep in mind that the result will be an antifreeze with intermediate properties depending on how you mix them. For example: mixing equal parts of 10% antifreeze with 50% antifreeze will give you 30%.
Mix water and antifreeze?
Antifreeze is often sold in concentrated form so the customer can mix it with water to the required concentration. However, this should be done with distilled or purified water to avoid sediment buildup in the cooling system. With this in mind, you can use this type of water to top up the coolant to the correct level for your car.
That said, keep in mind that if you dilute your antifreeze further, you'll not only reduce its ability to withstand cold and heat , but you'll also lose its anti-corrosion properties . This is definitely not recommended for your car. Only do this in an emergency, and as soon as possible, replace all the fluid with new fluid of the correct concentration. When you do, don't forget to bleed the system.
Images 2, 4, 5, 6 and 7 – Mike Mozart, Anthony Easton, ms.akr, zhouxuan12345678, Júlia Moésia