Windshield Washer Fluid for Every Season

What is the difference between summer and winter screen wash?

The two types are optimized for different conditions. The table below shows the key differences at a glance.

	Summer screen wash	Winter screen wash
Main cleaning target	Insects, pollen, and traffic film	Road salt, slush, and winter road grime
Freeze protection	Little to none; can freeze at or below 0°C	Rated protection (e.g. down to -15°C) when used undiluted
When to use	Spring, summer, and autumn; mild climates above freezing	When night temperatures approach 0°C or below, especially if you park outside
Risk if used in wrong season	Reservoir, pump, and nozzles can freeze; poor salt removal	Safe to use, though in very warm months you may prefer summer fluid for optimal insect removal

Switch to a winter screen wash before the first frost, ideally when night temperatures consistently drop below about 5 degrees Celsius. If your reservoir still has summer fluid in it, do not simply top it up with winter product. Mixing the two reduces the effective freeze protection of the winter fluid. If serious frost is expected, drain the reservoir first and refill with winter screen wash at full strength.

Some markets offer all-season fluids as a compromise for mild winters. DPP offers separate summer and winter products so you get the right balance for each season. Winter screen wash is safe to leave in the car year-round, though in warm months you can switch back to summer fluid for better insect removal. If you drive from a mild region into a much colder one, plan to use a winter fluid rated for the coldest temperatures you will encounter. For detailed advice on planning fluid choice across different climates, a seasonal maintenance guide is the better reference.

For cold conditions, night temperatures near or below 0°C, or a car parked outside in winter: Velorest Screen Wash Winter 5L.
For spring, summer, and autumn use and everyday top-ups above freezing: Velorest Screen Wash Summer 5L.

Do I need to dilute this, or does it go straight into the reservoir?

Both Velorest Screen Wash Summer 5L and Velorest Screen Wash Winter 5L are ready-to-use products. They go directly into the reservoir without adding water.

Situation	What to do
Ready-to-use product (both Velorest products)	Pour directly into the reservoir; no water added
Partial reservoir of summer fluid, winter approaching	Drain first, then fill completely with winter fluid at full strength
Topped up with water after partial use	Freeze protection is now lower than the label states; in cold weather, replace with fresh winter fluid

Adding water to a ready-to-use product reduces both cleaning performance and freeze protection below the rated temperature on the label. If you ever use a concentrate rather than a ready-to-use product, follow the mixing ratio on that label. Tap water is generally acceptable for diluting concentrates, though in areas with very hard water you may get limescale deposits over time; distilled water avoids that, but it is not essential for ready-to-use products. This page focuses on ready-to-use products; if you use a concentrate, its label will give you the correct ratio.

Two things to keep out of the washer reservoir entirely. Plain tap water, even in summer, leaves limescale deposits in the reservoir and nozzles, does not clean effectively, and offers no freeze protection for cooler months. Household glass cleaners and kitchen detergents are equally unsuitable: they can foam excessively, damage pump seals, and leave a film on the windshield that causes glare, particularly at night.

Is this fluid safe for my car, wipers, and modern sensors?

Rain sensors and cameras (ADAS). Standard automotive windshield washer fluid is compatible with rain sensors, lane assist cameras, and other forward-facing sensors when it is smear-free and used as directed. Both Velorest products are formulated to avoid leaving a film on the glass under normal use.
Wiper blades and rubber. Quality screen wash is designed to be safe for wiper rubber at normal concentrations and can reduce friction between the blade and glass. It does not, however, repair a worn blade; a blade that smears or skips still needs replacing.
Paint and plastic trim. Overspray onto paintwork and plastic trim is not a problem under normal use and does not cause staining. Wiping off any heavier spills is a sensible habit.
EVs and hybrids. Electric, hybrid, petrol, and diesel cars all use similar washer systems. Washer fluid is independent of engine or fuel type, so the same product works across all of them.
Warranty. Using a standard automotive windshield washer fluid as directed does not affect your vehicle warranty. Using non-automotive chemicals, such as household cleaners or solvents, in the washer system can cause damage and may complicate a warranty discussion if something fails as a result.
Glass coatings and tints. Standard automotive washer fluid is generally safe on factory glass, tinted windows, and common hydrophobic coatings. For specialised aftermarket coatings or window films, check the coating manufacturer's instructions. A detailed guide on how washer fluid interacts with hydrophobic treatments belongs in a glass care article rather than here.

The relevant compatibility question is always the washer system and the glass, not the engine or fuel type.

How often should you top up, and when is it time to flush the system?

Before every long trip: check the washer fluid level and top up if it is near the minimum. An empty reservoir on a motorway is a safety risk.
Every few weeks in winter: consumption rises sharply in cold weather due to salt and slush, so check the level more regularly and refill as needed.
Before the first frost: replace old summer fluid with winter fluid rather than just topping up, so you get the full freeze protection of the winter product.
If the fluid smells bad or looks cloudy: drain the reservoir completely and refill with fresh screen wash. Cloudiness or an unpleasant smell can point to algae growth or contamination.
After using plain water or a household cleaner by mistake: flush the system by draining the tank, refilling with proper screen wash, and spraying until only the new fluid comes through the nozzles. If the pump sounds noisy or weak afterwards, have a garage check it.

For refilling, look for the cap marked with a windshield or water-spray symbol, usually on the driver's side of the engine bay. Open it carefully and pour slowly; a funnel is worth using to avoid spills. Do not fill above the maximum mark if one is present. If any fluid spills onto hot engine components, wipe it off promptly. Keep screen wash out of reach of children and avoid eye contact when handling it.

Streaks, weak spray, or frozen jets: is it the fluid or something else?

Symptom	Most likely cause	Action
Streaks after washing	Worn or dirty wiper blades	Clean or replace the wiper blades first; if streaks remain with fresh blades and proper fluid, have the glass checked
Smearing film on glass	Wrong product, plain water, or household cleaner residue	Drain the reservoir, flush with proper automotive washer fluid, and use a glass cleaner to remove residue from the windshield
Weak or uneven spray	Clogged nozzles or a failing pump	Check and clean the nozzles; if the pump is still weak or noisy, go to a garage
No spray in cold weather	Washer fluid frozen in reservoir or lines	Move the car to a warmer place to thaw; once thawed, replace the fluid with winter screen wash. If the pump does not work afterwards, have a mechanic check it
Persistent streaks after new blades	Pitted or damaged glass, or heavy coating residue	Have a glass specialist or garage inspect the windshield

Simple nozzle cleaning can often be done at home, but for a step-by-step guide on that, a dedicated how-to article is the right place to look. Washer fluid is a preventive product; when the system stops working, the cause is almost always worn parts or a blocked nozzle, not the fluid itself.

Frequently asked questions

Can I put household glass cleaner in my washer tank?

No. Household glass cleaners and kitchen detergents foam excessively in the washer system, can damage pump seals, and leave a film on the windshield that creates glare at night. Use only products designed for automotive washer systems.

Does using this washer fluid affect my car's warranty?

Using a standard automotive washer fluid as directed does not affect your warranty. Using non-automotive chemicals in the washer system might, if they cause damage to the pump, seals, or reservoir.

Is it safe to mix summer and winter washer fluid?

It is not dangerous for the car, but mixing the two reduces the effective freeze protection below what the winter product would provide on its own. Before serious frost, drain the reservoir and refill with pure winter fluid to be sure of the rated protection.

If you are unsure whether to choose summer or winter fluid, the deciding factor is simple: check the overnight temperature forecast for the coming weeks. Below 5 degrees Celsius at night, winter screen wash is the right choice.