Screenwash may not be the most glamorous accessory, but drive your car without it, and you’ll soon notice its absence. As you travel, dirt builds up on your windscreen, and just using the wipers alone won’t be effective – plus, you run the risk of scratching your windscreen glass.
This is why screenwash is so important, if debris build-up restricts your view or the sun glares onto the windscreen and the dirt is blocking your vision. Equally important, a good screenwash-to-water and/or antifreeze ratio in the reservoir can help prevent your washer fluid from freezing.
The best screenwash at a glance:
And while it may be tempting to just pick up any old bottle of cheap screenwash from the supermarket petrol station, you can get a better product with far superior performance if you’re prepared to look around. For deep cleaning of your windscreen and windows, it’s worth considering investing in car glass cleaner to help clear those remaining marks.
What is screenwash and why does it matter?
Screenwash (also known as windscreen wiper fluid or washer fluid) is a specially formulated fluid used in a vehicle’s washer system to help the wipers remove dirt, insects, salt, and road grime, ensuring clear visibility in all driving conditions. You can almost think of it as car shampoo for your windscreen
The role of screenwash in safe driving is that it’s vital for a clear windscreen and good visibility as it improves wiper performance by preventing smears. It often contains an antifreeze to stay effective in winter.
You shouldn’t just use tap water, either. It might work in an emergency, but it’s no substitute for screenwash. It lacks the cleaning power to tackle insects and grime, it can freeze in cold weather, and it can clog washer jets with its natural mineral deposits. Screenwash is specially formulated to clean effectively, resist freezing, and protect your system.
How to choose the right screenwash for your needs
Seasonal screenwash: winter vs summer formulas
For colder weather, winter screenwash contains antifreeze agents to prevent freezing in low temperatures (often down to -10°C or lower). It cuts through road salt, slush, and greasy winter grime and is essential for winter driving. Keeping your alloy wheels clean is also useful during the cold season.
For warmer months, summer screenwash focuses on removing bugs, pollen, dust, and traffic film. It has little or no antifreeze, so it’s often cheaper and tailored for warmer conditions.
Concentrated vs ready-mixed: which is better?
Like some car pre wash products, concentrated screenwash must be diluted with water before use. They require less packaging, so concentrated products are more cost-effective and eco-friendly and they also allow you to adjust strength based on season or needs.
Ready-mixed screenwash is pre-diluted and ready to pour, which makes it convenient and hassle-free. It’s usually a bit pricier per litre, but it’s ideal for quick top-ups, and the consistent formula means there are no mixing errors. If you prefer convenience, go ready-mixed. For flexibility and value, concentrated is best.
Key ingredients to look for (and avoid)
It’s important to look for surfactants to break down grease, dirt, and bugs for effective cleaning. Alcohols will help prevent freezing and enhance cleaning power. Similarly, anti-freeze agents will protect against freezing in cold weather, and water conditioners will prevent mineral build-up and protect washer jets.
If you have small children, it’s worth looking for a screenwash that contains Bitrex, the most bitter-tasting substance in the world. It’s added to prevent accidental poisoning, should a child or pet intake a small amount. In short, it prevents serious harm from the toxic chemicals used to make screenwash.
You should avoid harsh acids or bleach, which can damage paint, rubber seals, and wiper blades. High concentrations of methanol can be toxic and potentially harmful if mishandled. Many modern screen washes avoid methanol due to its toxicity.
How we tested screenwash
Each screenwash product was put to the test in a number of different cars. These were both our own personal vehicles and long-term press loans. We followed each of the instructions carefully and diluted each of the products accordingly to the specifications.
Quite simply, we then tested them to see how good they are at cleaning the windscreen with the average build-up of dirt, bugs and grime. The best screenwash will be the one that is the most effective at doing so. We also look out for things such as value for money and ease of use – the latter relating to the dilution instructions. All of which will be tied into our overall score of the product.
The best screenwash tested by Parkers 2025
The best screenwash
I've been using it for a couple of months in our family Volvo. I had to scratch my head a few times to understand the dilution instructions. I assumed the Optimum Clean ratio (1:9) was best for most weather conditions, so I went with that just before one of the heatwaves picked up.
The car itself tends to chew through a lot of screenwash. That was the case before with the Prestone stuff (reviewed below), but I can confirm that when loaded up with Autoglym, it clears off every last bit of smudge, bug, and dirt there is. For the money, I wasn't expecting great performance, but it succeeded my expectations and is now my go-to for anything and everything screenwash.
Nice job, Letchworth.
Review by Aaron Hussain
Pros
- Exceptional performance in both warm and cold weather conditions
- Quality product which easily clears dirt off the windscreen
- Excellent value for money at just £6 for 500ml of product
Cons
- Isn't mixed, so requires diluiting before use
- The instructions aren't the easiest to follow - especially if you're just topping up
| Volume | 500ml |
| Type | Concentrated |
| Temperature range | Down to -45°C |
Editor's pick
Several bottles were gathered before testing, and I've been getting through a couple of them since. How has it performed? The simple answer is amazingly well. The windscreen feels slick and clean once the wipers get going, and in the case of my 40-year-old Mercedes, it works exceptionally well on the front headlights. The screenwash and little wipers for those help clear away bugs and grime effortlessly.
Does the cleaning quality of it succeed the Autoglym screenwash? Honestly, I reckon it's a tie between the two. Liqui Moly's lacks behind simply due to it costing twice as much for half the contents.
Saying that, I love the little top section of the bottle. There's a little reservoir which you squeeze the screenwash into, which has measurement levels. This is super-useful, considering how precise you have to be with the stuff, so that's a welcome touch.
Review by Aaron Hussain
Pros
- Worked brilliantly on the headlights as well as the windscreen
- Effortlessly clears any dirt, grime and streaks from the windscreen
- Has a handy measurement section just below the cap
Cons
- You need to buy these in bulk, ideally - each bottle is only 250ml big
- Not as good value for money as the Autoglym screenwash
| Volume | 250ml |
| Type | Concentrated |
| Temperature range | Not stated |
The best value screenwash
I've been using a bottle that we bought for our Volvo for the best part of several months. While five litres of screenwash is a lot for a mere £14, I'm not convinced it's the best-performing out there.
It takes a good couple of sprays to really clear the windscreen of motorway dirt, bugs and grime. What intrigued me was the part stating that the screenwash leaves a repelling layer on the windscreen to discourage things like road spray. Having done many trips with this screenwash armed, I don't think it repels as much as it claims. It's quite mild despite following the ratio instructions, and shouldn't be treated as a rain repellent replacement.
Where value is concerned, Prestone's screenwash is perfectly fine if you want a huge bulk of screenwash for little money. But it isn't the best performing on our test.
Review by Aaron Hussain
Pros
- Exceptional value for money at £14 for 5L of screenwash
- Good enough performer for what it is, and clears debris away easily
- Will last a long time, which is a neat bonus
Cons
- The cleaning performance isn't as strong as others
- I didn't notice the rain repellence properties so much
| Volume | 5L |
| Type | Concentrated |
| Temperature range | Down to -23°C |
The best rain repellent screen wash
Rain-X Concentrated Screenwash is designed to combine the effectiveness of rain repellent with your traditional screenwash; cleaning the dirt off, while leaving a repellent layer for rain and debris to slide off.
As a result, it helps keep your windscreen clear year-round. Add it undiluted to your washer bottle for winter motoring, and it'll offer protection down to -15°C.
During the summer months, you can use it diluted—one part screenwash to four parts water—but in winter or summer, it'll remove all kinds of dirt from the windscreen and leave a water-beading film on the windscreen glass.
Pros
- Designed for use all-year round, so dilution levels won't be a big issue
- Leaves a water-repellent film on windscreen, which helps in heavy downpours
- Good value for money at around £13 for five litres of product
Cons
- Isn't as effective as the standalone Rain-X product, if that's what you're after
| Volume | 5L |
| Type | Diluted |
| Temperature range | Down to -20°C |
The best eco-friendly screenwash
You can use up to five litres of water per-tablet, so they're efficient things to use. And for well-under £10 for a pack of eight, they represent good value for money as well. They're effective down to -4 degrees and claim to tackle anything from bird droppings, bugs, road grime and even tree sap.
They even claim to be more efficient than traditional screenwash. We haven't had the chance to test that out for ourselves, but it's promising stuff from the AA - and they're undoubtedly easier to store than a large five-litre plastic bottle.
Pros
- A more eco-friendly choice than traditional screenwash fluid
- Compact packets which can be left in your glovebox
- Two packs total up to 40-litres of screenwash
Cons
- Reportedly takes a while to dissolve, which isn't ideal
| Volume | 8-pieces |
| Type | Tablets |
| Temperature range | Down to -4°C |
Best ready to use screenwash
We like how you can simply just pour it in and go. It also costs a mere £4.59 for five litres, so it's amazingly good value for money, considering it's a mixed screenwash formula.
Where value is concerned as well as longevity, Holts' Ready To Use is a sensible choice, but don't expect the very best in cleaning like the others above.
Pros
- Diluted already, which makes it easier to use than concentrated screenwashes
- Amazing value for money at under £5 for five litres of product
- Is good enough at clearing debris off the windscreen
Cons
- Doesn't last as long as concentrated screenwash
- Cleaning performance isn't the best out there, but you can't expect so at this price point
| Volume | 5L |
| Type | Diluted |
| Temperature range | Down to -10°C |
How much screenwash should you use?
If you’re using ready-mixed screenwash, simply pour it in until the bottle is empty or the reservoir is full. With concentrated screenwash, you’ll need to dilute it with water, and the ratio depends on the season. In summer, a mix of 1:10 or 1:20 (screenwash to water) is usually fine. In winter, stronger protection is needed, so ratios of 1:1 or even 2:1 are recommended, meaning equal parts or twice as much screenwash as water.
DIY tips for refilling without spills
The best tip is to use a funnel; it makes it so much easier. If you don’t have one, you can make a temporary funnel by cutting the bottom off a plastic bottle. Pouring slowly is another good practice, as this prevents water from splashing back. If you prefer, you might find it easier to transfer the fluid to a container with a pouring spout to give you more control. Below, we’ve put together a short video with Affiliate Operations Editor Adam Binnie to demonstrate how to top up screenwash.
How to top up screenwash
FAQs
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How often should you top up screenwash?
It depends on vehicle use and driving conditions. In summer, a weekly check and a monthly top-up might be fine, whereas in winter, you might find you could use all your screenwash during a single motorway journey. Many modern cars have a low screenwash warning light - don’t ignore it, especially in poor weather
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Can screenwash freeze in the tank?
Yes, it is possible, especially if the temperature goes particularly low and the screenwash mix is weak. In winter, go with a 1:1 or even 2:1 ratio (screenwash to water) for proper freeze protection.
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Is screenwash a legal requirement in the UK?
While there’s no law that specifically says 'you must have screenwash,' the law does require that:
❝All vehicles must have a working windscreen washer system that can clean the windscreen.❞
— The Road Vehicles (Construction and Use) Regulations 1986
So, if your windscreen washer bottle is empty and you can't clean your screen, you’re breaking the law. -
Will screenwash remove bugs?
A good quality screenwash should tackle bugs easily. Bird droppings may prove more difficult, especially if they have dried. Tree sap is sticky and resinous, and most standard screenwashes won’t be able to get rid of it effectively.
You’ll probably need a glass cleaner or a bird poo remover and get to work on it with a microfibre cloth and a bit of elbow grease. -
Can you use any screenwash with rain-sensing wipers or heated jets?
Any good-quality screenwash is generally suitable for most vehicles with rain-sensing wipers and heated washer jets. In general, it's best to avoid additives that leave residues, as these can create films that interfere with sensor accuracy or clog heated jets.
Smear-free formulas will help prevent streaks that might confuse sensors and cameras. It's always a good idea to check your manufacturer’s recommendations, as some specify particular screenwash types to ensure optimal sensor performance and avoid damage. -
Is screenwash universal?
Yes, while most screenwash products are universal, some vehicle manufacturers may recommend or require specific formulations which need to be followed closely for the best results.
Always check your vehicle’s owner manual or manufacturer guidelines before choosing a screenwash, particularly if your car has unique features or warranty conditions. When in doubt, opt for high-quality, branded screenwash products that meet industry standards.
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