hello, in october i bought my new skoda octavia from volkswagen, the coolant level is dropping and it is at a minimum now, knowing that my car has only driven 4000km. i called volkswagen and they told me it's normal and i need to add coolant (g13).

i need your advices plz

Quite common for small air bubbles, introduced in the factory fill process, to disperse causing the level to drop. 
Unless level keeps dropping nothing to worry about.

Yerr - but be careful.  We've had several members who have had issues with the coolant expansion tank caps 'failing' - and coolant disappearing.  Invest in some ready mixed G12evo or G12++.  TDI engines do use coolant (I have had many TDI engines [150s and 184s] and they all seem to use coolant around regen time.  Weekly checks under the bonnet are a good thing.

they told me i should put G13, they have only G13 or G12pro(already mixed). if i use 1 litre of G13 how many  water should i add  plz?

What does the bottle say?

 

At a guess, you'll probably want it 1:1 for the UK:

It all depends - if you have concentrate, then mix accordingly - if you have ready mixed down to -36C, then just pour in.

G13 is now retired to be replaced by G12evo or G12++ (don't ask).

15 hours ago, langers2k said:

What does the bottle say?

 

At a guess, you'll probably want it 1:1 for the UK:

hello, I am currently in Tunisia and the temperature is different here, between 0 ° and 45 °, which mixture should I choose please?
mixed with g13, g12evo, g12 ++ is not a problem?

5 hours ago, Midoutn said:

mixed with g13, g12evo, g12 ++ is not a problem?

Short answer is no.

5 hours ago, Midoutn said:

Tunisia and the temperature is different here, between 0 ° and 45 °

Wind chill could take you down to more like -10° at night on the highway. If you're not using pre-mixed, mix 1-1 with deionised water.

Wind Chill does not take the temperature down.  Well not the coolant in the cooling system.

& not lower than the Air or Ground temp. It can cause quicker cooling down to the air temperature.

The same discussion has been had with windscreen wash over the years on Briskoda.

 

http://wheels.ca/news/should-you-factor-in-wind-chill-when-pouring-antifreeze

 

 

 

Edited 2 June, 20215 yr by e-Roottoot

Why does a radiator have a fan then? 

Drawing air through or as was with fans in front of radiators pushing air through and taking the temperature back down of the Summer Coolant / Antifreeze, or Oil with Air Coolers.

& Oil is also a coolant.

 

The fans operate at lower road speeds or when stopped as at higher road speeds it is the airflow through the grill that cools the radiators.

More surface area of Radiator / more fins the better.

 

In winter maybe block the cooling to the radiator from cold ambient air.

 

Listen to the weather people.   Windchill 'feels like.'  

That is on skin / living flesh and a measure of how the temperature will feel with cold / wind and drawing out heat.

Edited 2 June, 20215 yr by e-Roottoot

To be fair, moisture really needs to be involved, like sweat or screenwash on surfaces for true wind-chill to occur via latent heat of evaporation. 

Indeed. Refrigeration.

 

But windchill is not lowering the Coolant, Diesel, Petrol etc lower than the Air / Grass-ground temp.   But the Ground temp or a few feet above the ground can be cooler than Air Temp at around 2 meter above the ground.

6 hours ago, e-Roottoot said:

The same discussion has been had with windscreen wash over the years on Briskoda

Yes, and I'm still waiting for your explanation as to why neat screenwash that was liquid in the bottle froze on my headlamps if wind chill isn't a thing. Why carburettor icing occurred on cars. Why radiators freeze when the engine coolant is above 0c...

@KenONeillYou will have to wait til hell freezes over.  That will likely be when it gets cold enough. 

It will not bring the temperature of the coolant lower than the air temp though.

You do changing the freezing point and the boiling point by not just using H20 in the pressurised system.

 

Reference Libraries, encyclopedias or search engines are useful, and if the answer is not to your liking try another one the answer might be different.

Edited 2 June, 20215 yr by e-Roottoot

Why carburettor icing occurred on cars.

 

Latent heat of vaporisation and pressure drop across a venturi.

 

The same could happen with headlight washers, not so much the pressure drop but the evaporation of the volatile screenwash cooling the liquid. Any nozzle in an airstream will act as a venturi, its how a pitot static tube works and the freezing of them have been responsable for aircraft disasters.

 

In general terms if you have a vehicle at the ambient temperature of say 5°c and you drive it through that air at high speed the friction will warm the surfaces in contact not cool them

Edited 2 June, 20215 yr by J.R.

On my series  land rover I get carb icing in cool damp conditions rather than  on below freezing days  you can open the bonnet and see white frost on the outside of the carb.

@e-Roottoot - Yes, I know that, and that means there is a chilling effect in the venturi.

& the coolant is in a container / system and not exposed to air so not going lower than the air temp,

which is different from the carb and the washer fluid that is out and about.

Edited 2 June, 20215 yr by e-Roottoot

In carbs there's generally a much bigger pressure drop pre-to-post throttle plate due to the low pressure in the intake manifold, I would say, than at the venturi. Obviously not at, or close to WOT. Also a much smaller gap to obstruct with ice at low throttle openings.

@e-Roottoot @Wino Still waiting for either of you to explain why my observations are actually wrong, rather than effects of the gas laws.

@Midoutndoes your car have a petrol or diesel engine?  

You only really need to add anything to the cooling system if the level falls below minimum (when completely cold), and given your location I would suggest you would be fine just adding water if it does need a small top-up.

Obviously if it keeps needing top-ups you will probably need to get some G12evo or whatever the next flavour of VW coolant is. But if it does you may also need to find the leak.

@KenONeillThis winter or even before i would like you to get a thermometer, take the air temp, and fasten the thermometer to the front of your car or bike.

Then drive, drive or ride as fast as you dare, and stop and read the temp on the thermometer.

Edited 2 June, 20215 yr by e-Roottoot

31 minutes ago, e-Roottoot said:

get a thermometer, take the air temp, and fasten the thermometer to the front of your car or bike.

Done it, and you know what - The gas laws don't apply to thermometers. They do apply to liquids and gases though.