winter screen wash

[Lord Voltermore]

Not rocket science  this one, but a timely reminder.

With the first heavy frost I thought I should check what Honda (or is it the main dealer?) had put into my new Mk4.

I syphoned some out by sucking on a length of plastic pipe. Its probably not a good idea, but I wanted to sample it - in the interests of science   ;   I do have a screen wash strength hydrometer, but couldn't find it     But it looked a very thin summer mix. 
 
   If you are just  doing  a seasonal mix  swap its easier just to empty it by running the washers. But don't run the pump for too long. Do it in short bursts.   

If you do suck  be careful not to get any in your mouth.  It could be harmful, and some screen washes contain 'Bitrex' which makes  them very bitter to stop you drinking it         Not as daft as it sounds    The 100:1 concentrate  summer screen wash I use has a very pleasant fruity smell . 
Another risk , I once bought a 2 year old car where the screen wash looked like chicken soup due to algae growth.  Yuck.  Lesson here is never use just plain water in summer . Use screen wash all year round.

In the uk most screen washes seem to be of the all season types that can be  a bit vague about their level of winter protection.    Those from continental Europe tend to quote a temperature rating , eg minus 60C .   

   But beware . Deciding which is best value when diluted is not a simple matter of maths.

I've just checked two in my garage.  One, made in Czechia ,  is rated  minus 30C. You might expect adding a litre of water  to a litre of screen wash will make  two litres of minus 15c.  Actually its only minus 10c.  You can only make 1.5 litres of minus 15c.

The other, made in Bulgaria, is rated at minus 50C.  mixed  with one part water (1:1) its   minus24C  (not bad)    2 parts water is only minus 11c.   3 parts water is only minus 5c .     The same brand sells ready mixed  minus 20c which works out  much better value.

This isn't just confined to cheaper brands. Its a matter of chemistry I think.  Modern cars can use a lot of screen wash . It  pays  to check the labels before doing the dilution maths. 

[VicW]

Screen wash is so cheap I put it in neat all year round.  Why does the screenwash have a dipstick, surely nobody actually checks what is in the container before they fill it up?

Vic.

[Lord Voltermore]

What dipstick?  I cant find one on my Mk 4. I just fill to the brim.  If some cars have them I suppose it might help when diluting, You wouldnt have to  keep a container of ready mixed. 
  I had to remove some as there was a frost and the new car was still brim full of what might have been water for all I knew.   

 Some uk brands of 'all season' are only good down to  minus 5c 'even used neat. Shop around and you may get this for £1 - £1.25 a litre.    At this price it may not be worth faffing around diluting, if you dont use much.  But minus 5 protection from freezing solid is pushing your luck, even in a  uk winter.  And wind chill can turn it to slush on the screen. 

I have used more than 2 litres in a single day on long journeys in dirty weather.  High mileage drivers can use quite a lot of the stuff   If like me they prefer better winter protection it could be costing  maybe  £2 a litre, possibly a lot more if you dont do any research.   The savings may not be massive  for some drivers , but I'd rather spend it on wine than screen wash.

My research was based on finding that a Kaufland supermarket in eastern europe  had at least 15  different variations in strengths , sizes and brands.  With the correct calculation you could save more than 70%.   And summer  100:1 concentrate worked out at only 5p a litre when mixed

[Jayt43]

Minus 5 is pretty lame. In my neck of the woods -20 is the minimum and -40 is pretty normal.

Usually I fill up with a "Christmas special" one particular oil company has on its forecourts. Smells of cinnamon and mulled wine (not an encouragement to drink drive I know - but nice all the same! )

[VicW]

A few years ago in Germany British Armed Forces used to put neat Vodka in their screenwash bottles because it was cheap.

Vic.

[madasafish]

Thirty five years ago I used to fill my washer bottle with -20C mix. I used to leave home at 5am and the the washer bottle was solid with ice within a mile.

Nowadays -5c mix would be fine.

In 1999 driving up to Scotland - near Kilmarnock - my car temperature gauge recoded -22C in one hollow..The screen iced up on the inside...

[embee]

I remember getting some aerosol de-icer when I was in Austria, which performed way better than anything you can get here in the UK. In continental climates they tend to take these things a bit more seriously. It's odd because you get less of a problem with screen icing overnight when it's way below zero much of the time, the air is much dryer. I was there one winter and it didn't get above -5C for a month and we never saw the sun, but it was dry. Here in the UK it tends to hover a bit each side of 0C so the air is often moist and results in heavy icing.

I've been using Prestone -18C stuff for a couple of years now and find it very good for the UK, where we seldom see anything much below -10C, unless in Scotland for example. Strong mix in winter, weaker in summer. Eurocarparts have it, it's also been in Tesco I noticed.
https://www.autoexpress.co.uk/product-reviews/65265/best-car-screen-wash-2021

[DERMOT]

https://cpc.farnell.com/unipart/udi600/de-icer-600ml-aerosol-15/dp/CP07850

Cpc farnel l at 1.85  600ml  delivered. Found CPC good for screen wash et c if you don't like visiting shops.

[culzean]

I use prestone minus 18 (?) or even minus 35 ( I think screenwash can freeze in nozzles due to wind chill from movement of car ).

I find auto glym pump spray de-icer very good, you do not need much.

[TnTkr]

When the road temperature gets below -10 °C salt can't melt the ice anymore and you don't need to use washer. To have a decent margin to that in wintertime, I use mix which freezes at around -18...-20 °C.

[Kremmen]

I always also keep mine topped up but at service time I was charged for '1 part screen wash' which I queried and got it discounted.

These days, if it's freezing out there mine stays in the garage

[culzean]

When the road temperature gets below -10 °C salt can't melt the ice anymore and you don't need to use washer. To have a decent margin to that in wintertime, I use mix which freezes at around -18...-20 °C.

I have noticed wind chill effect on nozzles, where the washer bottle contents are still liquid but the nozzles freeze up, so even in UK I use a lower freezing point screenwash than would seem necessary ( -25 or more ),  also the alcohol based anti-freeze in screenwash can evaporate - meaning the screenwash can freeze at a higher temperature.   Most screenwash reservoirs are outside the engine compartment so get no help from heat of engine.

[madasafish]

I recall leaving home at 5am for work in the 1980s.The Sierra I drove had the screenwash bottle behind the mudshields in front of the front wheels.
Despite using -20C screenwash neat, the bottle or the nozzles  froze within the first 10 minutes of so of driving and remained frozen for the next hour or so until I got South of Birmingham. (In those day I ran in early mornings and local water  springs meant high roads were often covered with 10-20cm of ice.)

The local climate has since warmed and we no longer see such cold winters and I don't get up so early :-)

[Neil Ives]

The local climate has since warmed and we no longer see such cold winters and I don't get up so early :-)

The local climate has since warmed and we no longer see such cold winters

[nowster]

The local climate has since warmed and we no longer see such cold winters and I don't get up so early :-)

The local climate has since warmed and we no longer see such cold winters

All we need a the static high pressure system like we had in December 2010 and most of the UK will see -10°C temps again. It was the first time I'd encountered powder snow in England.

The UK is at the same latitude as bits of Canada that don't have much in the way of settlements, but the North Atlantic drift (Gulf Stream) warms us.