Cartechnic CT12 plus / pure
Cartechnic CT12 plus / diluted
VW G13 / pure
VW G13 / diluted
Automotive antifreeze, also called coolant, is the liquid which is used in the radiator and cooling system of an internal combustion engine for vehicles.
The main ingredient in most coolants is ethylene glycol or propylene glycol. Automotive antifreeze keeps the cooling water from freezing in winter and from boiling in summer. A further task is to lubricate the cooling system, such as the water pump. Most antifreezes contain corrosion inhibitors and other additives, like foam depressants.
Besides its use in radiator systems, automotive antifreeze mixed with water is also a heat transfer liquid for cooling thermostats or circulators used in labs.
Common mixtures are 50:50 or 40:60 of antifreeze : water. Other mixtures are 30:70 or 20:80 of antifreeze : water (% by volume). Mixtures with lower antifreeze content have also lower viscosity, which leads to less flow resistance and less load of the thermostat's pump.
Such liquids can be used for flow temperatures down to -25°C, depending on the application the thermostat is used for. Below this temperature the flow resistance due to increasing viscosity (and possibly long hoses with quick connectors) is too high for proper cooling performance.
| Temp. [°C] | Dyn. Viscosity [mPa.s] | Kin. Viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 31.72 | 28.12 | 1.1282 |
| 15 | 40.86 | 36.11 | 1.1316 |
| 10 | 53.59 | 47.22 | 1.135 |
| 5 | 71.72 | 63.01 | 1.1383 |
| 0 | 98.15 | 85.98 | 1.1416 |
| -5 | 137.63 | 120.22 | 1.1448 |
| -10 | 198.25 | 172.68 | 1.1481 |
| -15 | 294.07 | 255.4 | 1.1514 |
| -20 | 450.54 | 390.18 | 1.1547 |
| -25 | 715.28 | 617.58 | 1.1582 |
| -30 | 1181.23 | 1016.9 | 1.1616 |
| -35 | 2036.19 | 1747.8 | 1.165 |
| -40 | 3662.42 | 3135.1 | 1.1682 |
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 45.37 | 39.72 | 1.1421 |
| 15 | 59.80 | 52.21 | 1.1455 |
| 10 | 80.03 | 69.66 | 1.1488 |
| 5 | 109.42 | 94.98 | 1.1521 |
| 0 | 153.14 | 132.55 | 1.1553 |
| -5 | 220.00 | 189.89 | 1.1586 |
| -10 | 325.09 | 279.80 | 1.1619 |
| -15 | 495.44 | 425.19 | 1.1652 |
| -20 | 780.88 | 668.19 | 1.1686 |
| -25 | 1276.40 | 1089.20 | 1.1720 |
| -30 | 2166.70 | 1843.70 | 1.1752 |
| -35 | 3841.20 | 3259.50 | 1.1784 |
| -40 | 7138.30 | 6040.80 | 1.1817 |
| -45 | 13914.00 | 11743.00 | 1.1848 |
[exact content of antifreeze, considering volume contraction: 63.15 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 6.34 | 5.8 | 1.0935 |
| 15 | 7.75 | 7.06 | 1.0964 |
| 10 | 9.53 | 8.67 | 1.0992 |
| 5 | 11.91 | 10.81 | 1.1019 |
| 0 | 15.14 | 13.71 | 1.1046 |
| -5 | 19.64 | 17.73 | 1.1073 |
| -10 | 26.04 | 23.46 | 1.1099 |
| -15 | 35.43 | 31.85 | 1.1125 |
| -20 | 49.65 | 44.53 | 1.115 |
| -25 | 71.79 | 64.24 | 1.1174 |
| -30 | 107.48 | 95.97 | 1.1199 |
| -35 | 167.29 | 149.07 | 1.1222 |
| -40 | 271.31 | 241.24 | 1.1247 |
| -45 | 459.01 | 407.24 | 1.1271 |
| -50 | 813.83 | 720.44 | 1.1296 |
[exact content of antifreeze, considering volume contraction: 51.8 % by vol]
| Temp. [°C] | Dyn. Viscosity [mPa.s] | Kin. Viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 3.98 | 3.72 | 1.0695 |
| 15 | 4.72 | 4.4 | 1.0721 |
| 10 | 5.69 | 5.29 | 1.0744 |
| 5 | 6.96 | 6.46 | 1.0777 |
| 0 | 8.66 | 8.02 | 1.0800 |
| -5 | 10.98 | 10.15 | 1.0822 |
| -10 | 14.23 | 13.13 | 1.0842 |
| -15 | 18.91 | 17.4 | 1.0863 |
| -20 | 25.83 | 23.74 | 1.0883 |
| -25 | 36.34 | 33.33 | 1.0903 |
| -30 | 52.96 | 48.49 | 1.0921 |
| -35 | 80.24 | 73.35 | 1.0939 |
| -40 | 126.95 | 115.86 | 1.0957 |
[exact content of antifreeze, considering volume contraction: 51.48 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 4.29 | 3.98 | 1.0771 |
| 15 | 5.14 | 4.76 | 1.0797 |
| 10 | 6.22 | 5.75 | 1.0824 |
| 5 | 7.64 | 7.04 | 1.0849 |
| 0 | 9.53 | 8.77 | 1.0873 |
| -5 | 12.14 | 11.14 | 1.0897 |
| -10 | 15.80 | 14.47 | 1.0919 |
| -15 | 21.08 | 19.27 | 1.0941 |
| -20 | 28.90 | 26.37 | 1.0962 |
| -25 | 40.91 | 37.25 | 1.0982 |
| -30 | 59.89 | 54.44 | 1.1001 |
| -35 | 91.03 | 82.60 | 1.1020 |
[exact content of antifreeze, considering volume contraction: 45.41 % by vol]
| Temp. [°C] | Dyn. Viscosity [mPa.s] | Kin. Viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 3.32 | 3.13 | 1.0612 |
| 15 | 3.95 | 3.71 | 1.0635 |
| 10 | 4.71 | 4.42 | 1.0659 |
| 5 | 5.72 | 5.35 | 1.0681 |
| 0 | 7.05 | 6.59 | 1.0702 |
| -5 | 8.88 | 8.28 | 1.0722 |
| -10 | 11.42 | 10.63 | 1.0741 |
| -15 | 15.06 | 14.00 | 1.0759 |
| -20 | 20.44 | 18.96 | 1.0776 |
| -25 | 28.51 | 26.42 | 1.0793 |
[exact content of antifreeze, considering volume contraction: 39.07 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 3.01 | 2.84 | 1.0591 |
| 15 | 3.54 | 3.34 | 1.0614 |
| 10 | 4.22 | 3.96 | 1.0636 |
| 5 | 5.09 | 4.78 | 1.0656 |
| 0 | 6.26 | 5.86 | 1.0676 |
| -5 | 7.85 | 7.34 | 1.0694 |
| -10 | 10.04 | 9.38 | 1.0710 |
| -15 | 13.18 | 12.29 | 1.0726 |
| -20 | 17.76 | 16.53 | 1.0740 |
[exact content of antifreeze, considering volume contraction: 34.42 % by vol]
| Temp. [°C] | Dyn. Viscosity [mPa.s] | Kin. Viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 2.49 | 2.38 | 1.0466 |
| 15 | 2.92 | 2.79 | 1.0484 |
| 10 | 3.45 | 3.29 | 1.0504 |
| 5 | 4.15 | 3.94 | 1.0521 |
| 0 | 5.07 | 4.81 | 1.0537 |
| -5 | 6.31 | 5.97 | 1.0568 |
| -10 | 8.05 | 7.61 | 1.0574 |
| -15 | 10.51 | 9.93 | 1.0584 |
| -20 | 14.13 | 13.34 | 1.059 |
[exact content of antifreeze, considering volume contraction: 29.64 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 2.34 | 2.24 | 1.0450 |
| 15 | 2.70 | 2.58 | 1.0470 |
| 10 | 3.18 | 3.04 | 1.0488 |
| 5 | 3.81 | 3.63 | 1.0505 |
| 0 | 4.63 | 4.41 | 1.0520 |
| -5 | 5.75 | 5.46 | 1.0533 |
| -10 | 7.28 | 6.90 | 1.0544 |
| -15 | 9.45 | 8.95 | 1.0553 |
[exact content of antifreeze, considering volume contraction: 23.21 % by vol]
| Temp. [°C] | Dyn. Viscosity [mPa.s] | Kin. Viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 1.86 | 1.80 | 1.0313 |
| 15 | 2.16 | 2.09 | 1.0327 |
| 10 | 2.53 | 2.45 | 1.0342 |
| 5 | 3.01 | 2.91 | 1.0355 |
| 0 | 3.65 | 3.52 | 1.0366 |
| -5 | 4.50 | 4.34 | 1.0374 |
| -10 | 5.67 | 5.46 | 1.0381 |
[exact content of antifreeze, considering volume contraction: 19.10 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 1.76 | 1.71 | 1.0288 |
| 15 | 2.01 | 1.95 | 1.0305 |
| 10 | 2.34 | 2.27 | 1.0319 |
| 5 | 2.76 | 2.67 | 1.0331 |
| 0 | 3.32 | 3.21 | 1.034 |
| -5 | 4.07 | 3.93 | 1.0347 |
| -10 | 5.09 | 4.92 | 1.0351 |
[exact content of antifreeze, considering volume contraction: 12.74 % by vol]
| Temp. [°C] | dyn. viscosity [mPa.s] | kin. viscosity [mm²/s] | Density [g/cm³] |
|---|---|---|---|
| 20 | 1.53 | 1.50 | 1.0188 |
| 15 | 1.72 | 1.69 | 1.0202 |
| 10 | 1.97 | 1.93 | 1.0213 |
| 5 | 2.29 | 2.24 | 1.0222 |
| 0 | 2.72 | 2.66 | 1.0228 |
| -5 | 3.31 | 3.23 | 1.0230 |
Due to volume contraction, the nominal relation values for the mixtures in % by volume are not exact in the above tables. Volume contraction in chemistry means that if mixing two different liquids the total volume is less than the sum of the single components' volumes. For example, if adding 100 mL of water to 100 mL of ethanol, the resulting volume is less than 200 mL. How strong this effect is depends on the components, but it is considerable if mixing water and alcohol.
The exact content of antifreeze in the tested mixtures in % by volume is given in brackets [ ].
See also the charts that show viscosity and density over exact concentration for several temperatures and both substances, CT12+ and VW G13.
Measured with SVM™.
| Reference | Measurement with SVM™ |
|---|---|
| Kin. vis. | yes |
| Dyn. vis. | yes |
| Density | yes |
| Multiple temperatures | yes |
| Related | Glycol, antifreeze, coolant, heat transfer liquid |
