Editing Coolant (section)

==Identification==
===Colours===
Coolants or antifreezes are usually dyed a strong colour.  Originally this was an almost-fluorescent green for easy identification.  Later formulations with different corrosion inhibitors were then dyed different colours, but a universal system has never been adopted.  Colours vary for the same chemical makeup between brands and in different regions of the world, and the same colours may be used for different chemical makeups.

Based on the colour alone, you might be able to take a guess at what the coolant is, but no guarantees:
*'''Orange''': almost always equivalent to GM Dex-Cool, 2-EHA-based
*'''Yellow''': G05-type lobrid ("heavy duty"), or "universal" (eg. Prestone), or plain OAT (eg. many trucks)
*'''Yellow-green''': probably Renault type D, used to be plain OAT, now Si-OAT (some POAT "green" coolants are pale and yellowish)
*'''Red''': usually plain OAT, sometimes 2-EHA-based, often more complex carboxylic acids or mixtures, to G12 or G12+ standard (note that OEM Toyota coolant for very old models is red HOAT)
*'''Pink''': usually an OAT that is safe to mix with other types of coolant, may be Si-OAT or PSi-OAT, to G12+, G12++, or G12 EVO standard, but Japanese (eg. Toyota) pink coolant is PHOAT
*'''Violet''' or '''lilac''': usually Si-OAT or PSi-OAT, to G12++ or G12 EVO standard, although Comma/Halfords sometimes describe their G30 as violet
*'''Purple''': glycerin-based Si-OAT to G13 standard
*'''Blue''', '''blue-green''': may be IAT, lobrid OAT, or PHOAT
*'''Green''': may be IAT or P(H)OAT (usually Japanese), or Si-OAT (BMW/Toyota HT-12)

===Brands and codes===
Coolant colour is not a reliable guide to what is actually in the coolant, so it is important both to check what is already in the system and what a new product is.  Mixing certain coolant types can produce sludge or thickening, or simply reduce the effectiveness and lifetime.  Different manufacturers and car brands use their own or semi-standard codes, but mostly these are a few basic types:
*'''IAT''': VW G11 TL 774C (blue), Comma Super Coldmaster, previously Classic (blue), Halfords Silicate (= Comma Super Coldmaster), ECP Triple QX Blue (blue), Granville Subzero (blue), Bluecol 2yr (blue)
*'''HOAT''': Comma/Glysantin G05 (yellow, with sodium benzoate and nitrites) BMW LC-87 (blue), Comma/Glysantin G48 (blue/green, with silicates), Halfords NAP-free (= Comma G48), Citroen/Peugeot/Opel/G33 (blue)
*'''OAT''', VW G12 TL 774D (red), VW G12+ TL 774F (pink), Comma Super Longlife Red (red), Halfords OAT (red), Comma/Glysantin G30 (violet), Glysantin G33 (blue/green), Glysantin G34 (orange), ECP Triple QX Red (red), ECP Triple QX Orange (orange), Havoline XLC (orange), Granville Zerocol (red), Bluecol 5yr (red), old Renault Type D (yellow-green)
*'''P-OAT/PHOAT''': Honda Type 2 and many other Japanese (blue), Renault Type E (blue), Toyota Super Long life (pink or blue)
*'''Si-OAT''': VW G12++ TL 774G (pink), VW G13 TL 774J (purple, with glycerin), ECP Triple QX Purple (purple, with glycerin), Havoline QFC (red, with glycerin), BMW LC-18 (green), Glysantin G40 (violet), new Renault Type D (yellow-green)
*'''PSi-OAT''': VW G12EVO (pink), Glysantin G64 (green), Glysantin G65 (=G64, but pink)