What's the Difference Between Different Coolant Colors?
3 Answers
Coolant color is not inherently related to its performance or quality. Different colors are primarily used for easy identification. Here are the specific details about coolant: 1. Total multi-function coolant is fluorescent green (Total multi-function coolant is specially prepared in a fluorescent green color by adding fluorescent substances, mainly to facilitate leak detection.), Caltex premium coolant is orange, Blue Star coolant is blue, and Tongli coolant is red. 2. Coolant itself is a colorless and transparent liquid. The reason these coolants are made in bright colors is mainly for easy differentiation and identification by adding some dyes, another purpose is to prevent accidental ingestion.
I recently discovered the importance of color differences when changing my car's coolant myself, mainly because different colors represent variations in chemical composition. For example, green coolant is mostly ethylene glycol-based with added silicate corrosion inhibitors, suitable for older cars. Blue coolant is often propylene glycol-based or uses organic acid technology (OAT), offering better environmental friendliness and compatibility with newer models. Pink coolant may be HOAT (Hybrid Organic Acid Technology) type, providing strong corrosion protection but with a longer lifespan. Colors act like identification codes to prevent mixing, as combining different formulations can cause sedimentation, clog pipes, and lead to engine overheating issues. When selecting coolant, don't just rely on color—always check your vehicle manual for the correct type. Older cars are particularly prone to mismatches, so I often remind friends to test compatibility before adding. If the color turns murky or deteriorates, replace it promptly to protect the cooling system and extend your car's lifespan.
Having worked in the auto shop for years, coolant color is a key indicator. Green typically indicates traditional silicate formulas, protecting older engines. Blue represents low-toxicity or organic acid formulas, reducing environmental impact. Red denotes HOAT or specific long-life types, used in newer models. Color standardization across the industry helps users identify and avoid mixing errors, as incorrect mixing can corrode radiators and cause major issues. For maintenance, it's recommended to change to the same color coolant every two years, checking compatibility lists beforehand. Brand colors may vary slightly, but the core principle is selecting the right type to prolong the system. Don't underestimate this color detail - post-mixing cleanup costs are high, and daily checks of color clarity reveal system health.
