Diluting screenwash correctly is essential for effective cleaning, streak-free visibility, and crucial frost protection for your vehicle's windshield. The optimal dilution for general use and temperatures down to -3°C is one part screenwash to nine parts water.
Why Dilute Screenwash?
Using screenwash correctly diluted offers several benefits beyond simply cleaning your windscreen:
- Effective Cleaning: It efficiently removes dirt, grime, insect remains, and road salt without leaving streaks.
- Frost Protection: Diluting according to temperature guidelines prevents the water in the washer system from freezing, which can damage pipes, pumps, and nozzles.
- Component Protection: The right dilution helps prevent limescale buildup in the system and is gentle on your car's paintwork, rubber seals, and wiper blades.
- Cost-Effective: Concentrated screenwash is designed to be diluted, making it last longer and providing better value.
- Improved Safety: Clear visibility is paramount for safe driving, and properly diluted screenwash ensures your windscreen remains spotless.
Understanding Dilution Ratios
The dilution ratio indicates how much screenwash concentrate you should mix with water. A ratio of "1 part screenwash to 9 parts water" means for every measure of screenwash, you add nine equal measures of water. For example, if you use 100ml of screenwash, you would add 900ml of water to make 1 litre of ready-to-use solution.
Dilution Guide for Different Temperatures
The ideal dilution ratio changes based on ambient temperatures to provide adequate frost protection.
| Temperature Range | Screenwash:Water Ratio | Notes |
|---|---|---|
| Down to -3°C | 1 part screenwash to 9 parts water | Optimal for everyday cleaning and mild frost protection. This ratio is effective for most year-round conditions in temperate climates. |
| Down to -45°C | Adjust concentration to suit conditions | For extremely cold conditions, such as during winter expeditions, a significantly higher concentration of screenwash is required to prevent freezing. |
Important Note: Always check the specific instructions on your screenwash product, as recommended ratios can vary slightly between brands.
How to Mix Screenwash Properly
Mixing screenwash is a simple process, but following these steps ensures optimal performance:
- Check Your Reservoir: Before adding new fluid, check the current level in your washer fluid reservoir, typically located under the bonnet and marked with a windscreen icon.
- Determine Your Ratio: Based on the current and expected temperatures, decide on the appropriate screenwash to water ratio (e.g., 1:9 for down to -3°C).
- Measure Accurately: Use a measuring jug to accurately pour the required amount of screenwash concentrate into the reservoir.
- Add Water: Top up the reservoir with the correct amount of water. For best results and to prevent limescale, consider using distilled or de-ionised water, although tap water is often acceptable if it's not too hard.
- Avoid Overfilling: Do not fill the reservoir past the "MAX" line.
- Secure Cap: Replace the reservoir cap securely.
Practical Tips for Using Screenwash
- Year-Round Use: While often associated with winter, screenwash is beneficial all year. A milder dilution in summer helps remove bugs and pollen.
- Don't Use Undiluted: Using concentrated screenwash undiluted is rarely necessary and can be wasteful. It can also potentially cause streaking or damage to some components.
- Never Use Plain Water: Plain water can freeze in colder temperatures, potentially damaging your washer system. It also lacks the cleaning agents found in screenwash.
- Check Regularly: Make it a habit to check your screenwash level regularly, especially before long journeys or when cold weather is forecast.
- Consider Pre-Mixed Solutions: If you prefer convenience or are unsure about mixing, pre-mixed screenwash solutions are available, designed for specific temperature ranges.
By properly diluting your screenwash, you ensure crystal-clear visibility, protect your car's systems, and maintain safety on the road in all weather conditions.
