How much thought do you give to your screenwash? If you’re like most people, you probably buy what’s available on the local petrol station forecourt once your car tells you you’ve run out.

But it might pay you to be a little more discerning about your choice of washer fluid. After all, the differences between brands might surprise you.

Of course, screenwash performs two roles: firstly, and somewhat unsurprisingly, it washes your screen. QED, no? But the second, equally important purpose of that vividly coloured fluid is to make sure your washer fluid doesn’t freeze in the colder months.

And if your screenwash can’t hack it, it isn’t just frozen washer jets that could pose a problem – you might also result in a cracked or leaking tank or split pipework.

So which screenwash is best? Well, to help you answer that question, we’ve put ten of the brands you’re most likely to find on the shelves to the test, in concentrated form. Here’s what we found.

1. Prestone Extreme Performance Concentrated Screenwash (5l)

Minimum temperature: -18C

5/5

Despite its affordable price, the Prestone screen wash offered one of the best cleans here, leaving our test screen almost entirely streak- and grime-free. It’s also a very concentrated formula for the money, which means it should be tough enough  in neat form to cope with even the worst British winters; diluted, meanwhile, you need to use less of it to achieve the same sort of protection as its competitors. All of which made it our winner.

2. AA All-Season Screenwash Tablets (x8)

£8.75 (£1.09/tablet) (Amazon)

Minimum temperature: -4C

4/5

A word of caution with any screen wash tablet: the dilution ratio is fixed. In other words, each of these pastilles makes up five litres, so if your you only need to top-up, you have some left-over, which takes up storage space if you want to avoid wasting it. Having said that, these tablets cleaned better than any other product in this test. It’s just a shame they don’t offer much resistance to low temperatures; they are quite good value, mind you, so it you could always use a booster to top up their protection in the depths of winter.

3. Halfords -10 Concentrate Screenwash (2l)

£4.99 (£2.50/litre) (Halfords)

Minimum temperature: -10C

4/5

This is one of several Halfords screenwashes – derivatives that protect down to -20C and -30C are also available, and all come in five-litre form as well as this two-litre version. That would reduce the unit price somewhat, though we couldn’t find the five-litre variant of this particular screenwash in our local store. This is one of our pricier options, but it did provide good protection in cold weather and respectable cleaning performance in our test, even if it wasn’t the very best on either count.

4. DriveTec Rain Repellant Screen Wash (5l)

£4.79 (£0.95/litre) (GSF Car Parts)

Minimum temperature: -10C

4/5

This is the only screen wash in our test that comes in at less than a pound a litre, making it the best value of all the liquid screen washes here, and a bargain considering it also includes a rain repellant that should help to fend off the worst of the rain even after it’s been applied.  Cleaning performance wasn’t as good as the best, but it certainly wasn’t the worst either; all round, this feels like a very respectable option for buyers watching the pennies.

5. Auto Glym Ultimate Screenwash (500ml)

£8.99 (£17.98/litre) (Halfords)

Minimum temperature: -45C

4/5

The most expensive option here, and while Auto Glym’s screenwash is also the most heavily concentrated, diluting it down to -6C strength results in 2.5 litres of washer fluid – which is about the same as you’d get from 1.25 litres of our other competitors in concentrated form. So even with its low minimum temperature, this is an expensive buy, and while it cleans well, it isn’t noticeably better than the rest. That said, if you pour it in neat you get the best cold temperature protection – though of course, you’ll have to use fair amount of it, for which your wallet won’t thank you.

6. TripleQX All Seasons Concentrated Screenwash (5l)

£5.29 (£1.06/litre) (Euro Car Parts)

Minimum temperature: unknown

3/5

At just £5.29 for a big bottle like this, the TripleQX screenwash is the second most affordable fluid here, which will tempt many buyers. Trouble is, it doesn’t clean brilliantly; what’s more, there’s no guideline given as to the protection it offers against freezing temperatures, so you have to pour it in and hope. Indeed, the instruction to ‘pour directly into screen wash bottle’ makes you think it should be used neat – so is it really a concentrate (rather than a ready-to-use solution) at all?

7. Holts Professional Concentrated Screenwash (5l)

£7.00 (£1.40/litre) (Euro Car Parts)

Minimum temperature: unknown

3/5

Holts, too, offers no guidance as to how cold its product will get before freezing. And the cleaning performance of this screenwash was fairly uninspiring – while it lifted dirt reasonably well, it still left lots of streaks. On the plus side, it isn’t too costly to buy, but then again it isn’t actually as cheap as it really should be, given its rather lacklustre performance.

8. Carplan All Seasons Concentrate (2.5l)

£8.66 (£3.46/litre) (Amazon)

Minimum temperature: -4C

2/5

Another fairly middle-of-the-road performer in terms of its cleaning ability. Trouble is, this Carplan product is priced as if it’s one of the best – and frankly we’d expect better from a screenwash whose price per litre is the second highest in this test. It doesn’t help that temperature protection is fairly mediocre – it’s probably enough for autumn or even a mild winter in southern England, but further north it probably won’t be strong enough.

9. No Nonsense Concentrated Screenwash (5l)

£7.99 (£1.60/litre) (Screwfix)

Minimum temperature: -4C

2/5

You don’t get indication of the minimum temperature this screenwash will protect down to on the bottle, though the Screwfix website says it’ll go down to -4, which again won’t really cut it in colder parts of the country. Cleaning performance was pretty disappointing, too, with lots of muck left on the screen after even a second pass with the wiper blade. What’s more, this is marketed as a budget option, but it isn’t actually all that cheap.

10. Unbranded screenwash tablets (x20)

£3.99 (£0.20/tablet) (Amazon)

Minimum temperature: 0C

1/5

There are dozens of versions of these unbranded screenwash tablets on Amazon, and they’re all very cost-effective, so we decided to try some here to see whether they’re any good. The answer is somewhat predictable. For one thing, there’s no sub-zero temperature protection – the minimum rated temperature is freezing point, so you’ll need something more in winter. They offered the worst clean here, too, and when we put the tablet in our bucket, it didn’t dissolve in a uniform way. In short, you get what you pay for.