Car wash dilution ratios: how much product and water?
Calculate a product-to-water ratio and distinguish water already measured from the total solution volume and foam-bottle concentration.
Making a total of 600mL at 1:5
If the volume ratio is product:water = 1:5, measure 100mL of concentrate and 500mL of water. The measured amounts total 600mL. If you already have 600mL of water, add 120mL of concentrate for a measured total of 720mL.
These numbers illustrate the calculation. They do not recommend 1:5 for every car wash product. First check whether your product permits dilution with water and which ratio it specifies for the surface and intended use.
Identify which number means product and which means water
Numbers such as 1:5 or 128:1 do not identify the product side by themselves. Read the manufacturer’s stated product and water amounts together. Distinguish Ready-to-Use (RTU) products from concentrates and do not dilute them arbitrarily.
The calculations here apply only when product:water = 1:N by volume has been established. Do not use the same formula for mass ratios, active-ingredient concentrations or an unexplained dilution factor. This is not a calculation for mixing different cleaning chemicals.
A target total versus water already measured
For a target measured total V, concentrate is V ÷ (N+1) and water is the remainder. One part concentrate plus N parts water makes N+1 parts. If you have already measured water W, concentrate is W ÷ N.
| Product:water condition | Amounts to measure |
|---|---|
| 1:5 · 600mL total | Concentrate 100mL / Water 500mL |
| 1:5 · 600mL water prepared | Concentrate 120mL / Water 600mL |
| 1:9 · 500mL total | Concentrate 50mL / Water 450mL |
| 1:19 · 1,000mL total | Concentrate 50mL / Water 950mL |
This is a practical calculation that adds measured volumes, not a laboratory method guaranteeing an exact final volume after mixing. If a product says to make up to a total of 1L with water, use that final mark. Do not reinterpret it as adding concentrate to 1L of water.
Bottle concentration is not the concentration reaching the car
A foam lance can mix additional water into the solution drawn from its bottle. Distinguish the bottle ratio from the concentration reaching the panel (PIR). For products specified by target PIR, follow the manufacturer’s equipment-specific measurement and adjustment method.
Calculating the concentrate amount does not establish the equipment settings. See snow foam for bottle versus panel concentration, dwell times and drying limits. The same product may have different dilution instructions for bucket, foam-lance and rinseless uses.
Follow the application conditions after calculating
Use measuring tools and containers appropriate to the product instructions. Follow the label and safety information for addition order, protective equipment and storage. If foam obscures the liquid mark, do not count foam height as liquid volume.
Check surface suitability, application, dwell time and rinsing separately from the calculation. Do not keep adding concentrate because cleaning is disappointing. If the dilution basis is unclear or the required amount exceeds the container capacity, check the product and equipment instructions before use.