Automotive coolant is available as a concentrate and ready-to-use antifreeze. From the first, you can independently prepare the second. In order to get a really non-freezing liquid from the concentrate, it must be diluted with water in a certain proportion. It depends on it at what temperature the finished antifreeze will begin to crystallize. In this material, we will talk about what antifreeze concentrate is, whether it can be poured in its pure form into the car's cooling system, how to dilute it, what water to use, and whether it is even profitable to do this.
The composition of the antifreeze concentrate
Antifreeze concentrate is practically pure ethylene glycol. Practically because most concentrates contain about 5% water. Ethylene glycol is a type of alcohol. Differs in ability to mix up with water. Also, the temperature range of boiling and freezing of the concentrate is much wider than that of water - from -13°C to + 196°C.
Don't be put off by such modest freezing temperatures. Of course it's better than water. But this is not the limit for ethylene glycol. The whole magic of the concentrate is that when water is added, this threshold can increase to -70°C. This is enough to operate a liquid-cooled engine almost anywhere on our planet.
When we buy ready-made antifreeze, it is nothing more than a concentrate diluted with water. In this case, the issues of water quality and the proportion of components are decided by the manufacturer. Naturally, not for free. But more on that later.
Concentrate to cooling system
I don’t even know if anyone comes up with the idea of pouring pure antifreeze concentrate into the engine of their car. But since there is such a possibility, we will briefly consider this issue. Do not use undiluted antifreeze concentrate. And that's why.
For starters, because it's not profitable. The cost of 1 liter of quality concentrate is approximately $5. Let's say the volume of the cooling system in your car is 4 liters. This means you will spend $20. If you buy ready-made antifreeze, then the same 4 liters will cost you only $10. Twice cheaper.
Do not forget that the freezing point of the concentrate is only -13°C. This is too low for many regions. Yes. Concentrate does not behave like water when it freezes. It does not turn into ice, which expands and destroys the cooling system from the inside. When crystallized, ethylene glycol turns into a thick "porridge" that cannot circulate through the cooling system and do its job.
More about freezing point
Water freezes at 0°C. Antifreeze concentrate at -13°C. By mixing water and concentrate, we can obtain a coolant with a freezing point of -4°C to -70°C. See the table below for how it works.
|
Freezing point and proportions |
||
|
Ethylene glycol, % |
Water, % |
Freezing point, °C |
|
0 |
100 |
0 |
|
10 |
90 |
-4 |
|
20 |
80 |
-7 |
|
30 |
70 |
-30 |
|
40 |
60 |
-25 |
|
50 |
50 |
-40 |
|
60 |
40 |
-60 |
|
65 |
35 |
-70 |
|
70 |
30 |
-60 |
|
80 |
20 |
-40 |
|
90 |
ten |
-25 |
|
100 |
0 |
-13 |
Note that up to 65% ethylene glycol concentration, the freezing point increases, and then decreases back. If we take into account the economic benefits, then from this table we need only the upper part of it.
How to dilute antifreeze concentrate: 3 ways
Not everyone is fluent in percentages and proportions, which complicates the application of the table in practice. Especially for you, I will give three specific examples, based on which you can easily prepare antifreeze from a concentrate with an accurate freezing point.
Example 1. Method 50 to 50
This is the easiest way. If you mix ethylene glycol with water in equal proportions, then you get antifreeze with a freezing point of -40°C. This is enough even for many northern regions of the planet. Therefore, if your air temperature never drops below -35°C in winter, use this method.
Let's say the volume of your car's cooling system is 4.75 liters. To prepare antifreeze using this method, you will need about 2.5 liters of concentrate and the same amount of water.
Example 2. For temperature -20°C
Let's consider a more complicated example. Let's say you need antifreeze with a freezing point of -20°C, and the volume of the car's cooling system is 5.3 liters. There is no such temperature in the table. And the volume is "inconvenient" for calculations. When the temperature value you need is not in the table, take the nearest available one. In this example it is -25 °C. The ratio of concentrate and water is 40 to 60 percent.
To solve this problem, you need a school proportion:
- 3 liters is 100% of the required coolant
- ? liters is 40% ethylene glycol
This proportion will allow you to find out how much concentrate is needed. It is solved according to the following principle: 40 × 5.3 / 100 = 2.12 liters. The remaining volume is water: 5.3 - 2.12 = 3.18 liters. For simplicity, you can round. Take 2.2 liters of concentrate and 3.2 liters of water.
Example 3. For proportions in fractions or parts
The proportions of concentrate dilution with water are sometimes indicated on the container, but not in percentages, but in shares or parts. How to prepare antifreeze if you want to use the manufacturer's recommendations on the label? Let's say that to obtain a liquid with a freezing point of -25°C, the manufacturer recommends mixing 1 part ethylene glycol and 1.5 parts water. And the volume of the cooling system of your car is 4.8 liters. How to solve this problem?
Let's look at the proportion again:
- 8 liters of coolant is 2.5 (1 + 1.5 parts)
- ? liters of ethylene glycol is 1 part
Similarly to the previous example, we consider how much concentrate you need: 1 × 4.8 / 2.5 = 1.92 liters. The rest is water: 4.8 - 1.92 = 2.88 liters. For ease of preparation, round up: 1.9 liters of concentrate and 2.9 liters of water. It can be even simpler: 2 liters of ethylene glycol and 3 liters of water. You will get 5 liters of coolant with a freezing point of -25°C.
About water
The quality of the water for diluting the antifreeze concentrate is very important. Bad water can cause your car's cooling system to clog up and build up quickly. As a result, this will become one of the causes of engine overheating (the rest are described in detail in a separate article at the link).
To avoid these problems, I recommend using distilled water. If you do not know where to buy it, take drinking water, which is sold in grocery stores. I strongly do not recommend taking water from a well, a well, a city water supply.
About benefit
I can list three benefits that you can get from making your own antifreeze from concentrated ethylene glycol:
- Freezing temperature. Manufacturers of finished antifreeze often exaggerate this indicator on the labels of their products. If you prepare the coolant with your own hands, you will definitely be sure that it will not freeze.
- Saving money. When you need to service only one car, you will not see much financial benefit. If you need to replace the coolant on several cars, and you also have free water, the savings will be tangible.
- antifreeze quality. Depends on both ethylene glycol and water used by the manufacturer. Buying a quality concentrate and getting good water is easier than finding a decent ready-made coolant.
There are no other special benefits. They can be found if you believe that manufacturers of ready-made antifreezes add components with anti-corrosion properties to the composition. In practice, nothing of the kind is added to liquids of this category.
Outcome
In the preparation of antifreeze with your own hands, three things are important: high-quality concentrate; pure water; correct proportions. If you take into account all these points, then you will get a coolant that will definitely not freeze, will not harm your car's cooling system, and is cheaper than ready-made antifreeze.
