What are the differences in coolant colors?

[DiOlive]

Coolants with ethylene glycol as the main material are green, while those with propylene glycol as the main material are reddish, and propylene glycol-based coolants are blue. Here are some related introductions: 1. To distinguish between different types of automotive coolants with varying functions, normally, automotive coolants are colorless. However, to differentiate them from water and prevent accidental ingestion, manufacturers add water-soluble colorants to the coolant, giving them different colors. Following this logic, it becomes easier to distinguish between the various automotive coolants available in the market. 2. Green ethylene glycol automotive coolant is primarily used in cold winters. Green coolant is also one of the most commonly used coolants in the market. The green ethylene glycol coolant utilizes the chemical properties of organic acid compounds to remove scale, thereby providing anti-corrosion effects. Additionally, ethylene glycol helps lower the freezing point of the liquid, preventing the car's engine from freezing. On the other hand, red coolant has a more limited range of applications and is therefore less commonly used. Moreover, there are precautions to consider when using coolant. Generally, it is not recommended to frequently change the type of coolant.

[ONora]

With over a decade of experience in auto repair, I can tell you that coolant color is no trivial matter. Common colors include green, blue, red, and orange. Green coolant is typically the traditional silicate type, suitable for older cast iron engines—it's budget-friendly but has a short lifespan, needing replacement every 2 years. Blue coolant usually contains Organic Acid Technology (OAT), offering superior anti-corrosion properties and protection for all-aluminum engines, lasting up to 5 years. Red or orange coolant is generally Hybrid Organic Acid Technology (HOAT), providing balanced performance and broad compatibility, favored by many German and American new car models. Different colors mean vastly different formulations; mixing them can lead to gel-like deposits clogging the system or even corroding the radiator. Before changing coolant, always check your maintenance manual and stick to the manufacturer-recommended color for reliability.