South African shelves are full of antifreeze marked 96%, 80%, 50%, 50/50, 25% and “summer coolant” — often side by side, at very different prices. They are not the same product, and pouring the wrong one straight into your car can leave you badly protected. Here is what the percentages actually mean.
The percentage is how much coolant is in the bottle
Antifreeze is glycol plus a corrosion-inhibitor package; the rest is water. A 96–100% product is a concentrate: it is not meant to go in neat, but to be diluted with deionised water. A 50/50 (or “RTU” — ready to use) product is already mixed to the ideal ratio at the factory: pour it straight in. A 25% “summer mix” is mostly water with enough coolant for corrosion protection and everyday top-ups — and a bargain-bin 20% product is barely more than coloured water.
More glycol is not automatically better
Neat concentrate actually transfers heat worse than a proper 50/50 mix, and maximum freeze protection sits at around 60–68% glycol, not 96%. Concentrate exists for flexibility and value — you choose the strength. With Greyhound Coolant / Antifreeze OAT G12 LL 100 (concentrate), dilution with deionised water gives roughly: 33% = –18 °C, 40% = –24 °C, 50% = –37 °C and 60% = –52 °C, with boil-over protection rising as well.
So which should you buy?
Most motorists: 50/50 ready-to-use. No mixing maths, no water-quality risk, correct –37 °C protection every time — and available in blue, red, green and yellow to match your system. Workshops and fleets: concentrate. The lowest cost per finished litre, mixed to the exact strength each vehicle needs. Warm-climate top-ups: summer mix. Far better than plain water, which protects nothing and dilutes the inhibitors already in your system. The one thing never to buy is the hosepipe.
Whatever the strength, check the chemistry
The percentage tells you how strong the mix is — not how good the inhibitors are. Many cheap high-percentage products still use old silicate (G11-type) chemistry. All Greyhound G-MOTO coolants, from the 100 concentrate to the 25 summer mix, use modern silicate-free OAT G12 long life chemistry that protects aluminium engines through extended service intervals. If you missed it, read our guide to G11 vs G12 coolant.
And the water matters too
Whenever you dilute concentrate, use deionised or demineralised water. Municipal and borehole water carry minerals that form scale and deplete inhibitors — Greyhound Deionised Water is available in 5L and 20L exactly for this.
Browse the full Coolant / Antifreeze OAT G12 LL range — concentrate, 50/50 RTU and summer mix, from 500ml to 20L. Global Quality. Local Pricing. Fast Decisions. Reliable Supply.