What is the difference between green, orange and red engine coolant?

The colours of engine cooling fluids, also known as engine coolant or antifreeze, can vary depending on the manufacturer, but typically, green, orange, and red are the most commonly used colours. The colour of the engine coolant usually indicates the type of chemical additives that are used in the coolant, which can affect its performance in different ways.

Green engine coolant, also known as ethylene glycol coolant, is the traditional coolant used in most vehicles. It has a greenish-yellow colour and is composed of a mixture of water and ethylene glycol, along with additives such as corrosion inhibitors, lubricants, and dyes. Green coolant is often recommended for use in older vehicles.

Orange engine coolant, also known as Dex-Cool, is a long-life coolant that is used in some newer vehicles. It has an orange colour and is composed of a mixture of water, ethylene glycol, and organic acids. Dex-Cool has a longer service life than traditional green coolant, and it is designed to provide better protection against corrosion.

Red engine coolant is typically used in some newer European and Asian vehicles. It has a reddish-pink colour and is composed of a mixture of water, ethylene glycol, and organic acids. Red coolant is similar to Dex-Cool in that it has a longer service life than traditional green coolant and is designed to provide better protection against corrosion.

It is important to note that mixing different types of engine coolant can lead to reduced performance and potential damage to the cooling system. Therefore, it is recommended to always use the type of engine coolant specified in the vehicle's owner's manual and to never mix different types of engine coolant.