Editing Coolant (section)

===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)