Walk down any South African parts-shop aisle and you will see antifreeze in every colour, marked G11, G12, OAT, “long life”, 96%, 50/50 and more. What do these codes actually mean — and does it matter which one goes into your car? In short: yes, it matters a lot. Here is the plain-language guide.
What do G11 and G12 mean?
The “G” codes come from the VW/Audi coolant specifications that the industry now uses as shorthand for coolant technology generations. G11 is the older inorganic/hybrid technology: it protects metal by coating every surface with silicates. G12 is modern Organic Acid Technology (OAT): silicate-free organic inhibitors that activate only where corrosion actually starts.
Why OAT (G12) beats older antifreeze
The difference shows up over time. Silicates in G11 coolant deplete quickly and can form deposits or gels that clog radiator passages. OAT inhibitors are virtually non-depleting, which is why G12 is called a long life coolant — many OEMs specify service intervals of 5 years / 250,000 km or more. G12 also suits the aluminium and mixed-metal cooling systems in modern petrol and diesel engines far better, keeps heat transfer efficient, and reduces water pump wear because there are no abrasive particulates.
Does coolant colour tell you anything?
No — colour is a dye, not a chemistry. A green coolant can be old G11 technology or modern OAT; a red one likewise. The rule for topping up is to match the technology, not the colour. All Greyhound G-MOTO ready-to-use coolants (blue, red, green and yellow) are the identical silicate-free OAT G12 LL formula, so any of them can top up any of the others safely.
Do you even need antifreeze in South Africa?
More than you might think — just not mainly for frost. In our climate, coolant’s biggest jobs are preventing summer boil-over, stopping corrosion and cavitation, and lubricating the water pump. Plain water does none of that, and every water top-up dilutes the inhibitors already in your system. Inland, Highveld and Karoo winters do drop below zero, so freeze protection still counts: our 50/50 ready-to-use coolant protects down to –37 °C.
Upgrading from G11 to G12
Good news: G11 and G12 are compatible, so topping up an older system with G12 does no harm. To get the full long-life benefit, drain and flush the cooling system, refill with G12, and use G12 for every top-up afterwards. Always check your vehicle manufacturer’s coolant specification.
Which format should you buy?
The Greyhound Coolant / Antifreeze OAT G12 LL range covers all three ways South Africans buy coolant: Concentrate (100) you dilute with deionised water to the protection you need, RTU 50/50 pre-mixed and ready to pour with –37 °C protection, and an economical Summer Mix (25) for everyday warm-climate top-ups. All are produced to a European formulation at ISO-certified facilities and meet ASTM D3306, BS 6580:1992/2010, AS 2108-2004 and G12 long-life OAT requirements — at local prices.
Browse the full Coolant / Antifreeze OAT G12 LL range, or see our oil & coolant FAQ for more answers. Global Quality. Local Pricing. Fast Decisions. Reliable Supply.