Purified or Deionized H2O

[Alex1978]

Firstly, what is the distinction?

Additionally, should I use this substance as a coolant additive for replenishing the radiator instead of using tap water?

Furthermore, the aforementioned considerations apply to the wind screen top-up as well.

[Rojoires]

It is highly recommended to use Mercedes ready mixed coolant as opposed to distilled water, since the latter is primarily employed for battery replenishment purposes.The presence of water inside the washer bottle is deemed acceptable.

[SkippyTom]

I use a solution of concentrated coolant, namely not of the MB kind, that is blended with de-ionised water. To clean my vehicle's windscreen, I use a solution of concentrated screenwash that has been diluted with tap water.

[MrGreedy]

It is important to use care. Due to the complete removal of ions, deionized water exhibits a surprisingly caustic nature, rendering it unsuitable for use as a coolant in radiators.

Consider this perspective: Tap water often contains a variety of ions, including calcium, magnesium, chloride, fluoride, and others. While these ions are not present in a saturated state, they form a somewhat stable solution. By removing all the existing ions, there is enough space available to acquire more ions, such as aluminium and iron, from a radiator or engine block. The user's text is already academic. The incorporation of a corrosion inhibitor/anti-freeze into a solution offers the additional function of mitigating the potential corrosive effects of deionized (DI) water on metallic surfaces.

[Blu_Ray_UK2007]

During the coolant replacement procedure, I used Fricofin coolant in conjunction with distilled water. Tap water is treated with various substances to ensure its potability, since the taste of pure water, consisting just of H2O, is often considered unpleasant. The presence of salts and minerals in tap water may lead to chemical reactions with various metals and alloys, resulting in the formation of rust. Consequently, the water undergoes electrolysis, which is undesirable in a cooling system. The need of establishing a robust connection between the engine block and chassis for grounding purposes arises from the potential corrosive effects of water or electrolyte inside the system, which, if left unaddressed, might gradually erode the internal components of a cast iron block. The observation has been made that cylinder head studs may undergo significant erosion inside the engine block, to the extent that they fracture when subjected to torque. I am primarily referring about Jaguar straight six engines, which include the use of high carbon steel studs that are put into a cast block.

 

[Alex1978]

Extensive explanations!
That means both tanks may use regular tap water.

[Rojoires]

A suitable coolant is composed of certain ingredients that enable it to maintain a lower temperature, unlike water which is prone to boiling. Therefore, the term "summer coolant" is used to describe the practise of using tap water in an engine, which may lead to increased heat and potential damage to the engine.

[Allan8932]

I like using Scottish tap water in its pure form, without any additional additives. I anticipate that those residing on the West coast will likely advocate for the preservation of water sourced from Loch Katrine, just as I advocate for the safeguarding of the water supply originating from Lintrathen.

[bvlenci]

I just purchased authentic MB coolant subsequent to replacing the thermostat on my CLK. The bottle explicitly instructs to dilute the coolant with tap water at a 1:1 ratio, in order to provide protection against temperatures as low as -37 Celsius.