Radiator Coolant


Many people use pure water as radiator coolant. This results in rusting which works as an insulator in the radiator so that the heat is not taken out as is required. This means the engine temperature operates above the designed temperatures thus shortening the life of the engine. The rust can be deposited on the thermostat and therefore the thermostat does not regulate the engine temperature properly. The rust could also be deposited in the cylinder head causing the uneven expansion/contraction of the cylinder head and untimely cracking which results in water flowing in the engine causing bearing knock.

Engine coolants are a blend of soft water and Neat engine coolant that makes the boiling point of the coolant to be higher than that of water. This enables the coolant not to boil even when the engine is overworked. It protects radiator from rusting thus making the cooling efficient. It keeps the thermostat clean so that it can effectively control engine temperature.

There are three types of coolants;


These were the original coolants used between 1920s to late 1990s. They are still widely used in Kenya. They contain phosphate and silicate corrosion inhibitors. They are recommended for use for 30,000Km or 2 years thereafter they start precipitating. They should be replaced after this period.

Slusol does not market this product.


This type of coolant contains organic carboxylates that remain soluble throughout the life of the coolant. It lasts 5 years or 150,000Km in the radiator. It represents modern technology coolant.

Delstar Long Life Coolant is OAT. The product is available in a ready to use form (RTU) which is already mixed with soft water and does not require further mixing.

We also have Delstar LL Coolant (Neat) that you can mix in your workshop. Make sure the water you are using is soft. You can mix in the ratio of 1:1 or 2:1 Neat coolant to water.


It represents a blend of silicate and carboxyklate technologies. Like OAT, this coolant lacks 5 years or 150Km.