Liquid Ballasting


Liquid ballasting can be done only on tires already fitted on rims and deflated.
DO NOT mount tires on rims with liquids or air-liquid mixtures

1. Tire Ballasting:
Ballasting can be recommended especially in O.T.R. drive tires to:

  • Improve traction in severe heavy conditions (e.g.: graders and dozers)
  • Reduce tire slippage
  • Reduce fuel consumption
  • Increase vehicle stability
  • Agility, Accessibility & Attention (AAA)
Liquid ballast greatly increases tire stiffness especially at lower operating pressures; for this reason it is not recommended for operating speed higher than 30 km/h due to increased difficulties in vehicle handling.

2. Liquid Ballast Types:

Some options are available in the market to ballast tires. Liquid filling should be around 75% of tire inner volume to optimize ballasting effect. Do not use higher quantities for safety reasons (pressure could rise without control during operation).

Following table shows general “pros” and “cons” of possible liquid solutions (50/100 water based mix):

Type Resist Vs. Freeze Weight Vs. Water Safety Cost
Water No Resist 0% Safe Free
Calcium Chloride (CaCl2) Upto -50°C +40% Corrosive Low
Propylene Glycol Upto -40°C 0% Safe High
Ethylene Glycol Upto -40°C 0% Toxic Medium
Windshield Washer Fluid Upto -30°C 0% Toxic Low


Due to higher specific weight and resistance to freeze, Calcium Chloride CaCl2 is often used in addition to water to ballast tire. The mixture is corrosive, so that a minimum 75% filling is recommended or a tire tube should be used to protect the rim surfaces from rusting.

3. CaCl2 - Liquid Ballast Table:

CaCl2 concentration can be varied depending on anti-freeze properties, as shown on following table:

CaCl2(Kg) / Water(lit) Sol. Spec Gravity @ 18 °C (Kg/l) Freezing Temp (°C) Swell Factor "S" (cc/l)
0 No Resist 0 0
0.13 1.06 -10 50
0.25 1.12 -20 100
0.37 1.18 -30 150
0.5 1.25 -40 200
0.6 1.30 -50 250
For intermediate values, linear interpolation of parameters can be used.


Tire size 26.5 R25 SR30 fitted on a dozer is ballasted with CaCl2 in the concentration of 0.37 [kg] each liter of water to bear a temperature of -30 [°C]. Determine volume of solution to be filled in and weight increase for each tire.

From the table of BKT tire volumes, total inner volume is 882 liter.

A standard 75% filling will be considered, which correspond to: 0.75 x 882 = 661 liter of solution The total amount of water needed will be calculated as:

Liquid Ballasting Formula

The quantity of CaCl2 will be calculated from the table of previous page:

0.37 x 575 = 213 kg of CaCl2

This means that to have 882 liters of CaCl2 solution 575 liters of water and 213 kg of CaCl2 will be mixed together

Weight increase for each tire will be:
575 + 213 = 788 kg

4. Precautions Using Ballasted Tires:

Tire ballasting must be done only after bead seating:
  • Deflate tire
  • Position the valve in topmost position
  • Remove valve core
  • Add liquid ballast till it overflows from the valve
  • Insert back the valve core
  • Final tire inflate to working conditions
  • To control tire pressure, position tire valve in the upmost point.
Verify that rim and valve can be used for liquid ballasting. In case of tubes, tube valve must be specific to prevent separation from tube rubber.

Procedures  mentioned are purely  suggestive and recommended practices. BKT holds no responsibility of any consequences thereof.  Data can be amended at any point without prior notice and at sole discretion of BKT.