What is the Difference Between Coolant Colors?
2 Answers
Coolant colors mainly have the following differences: 1. Coolants of different colors have the same functions, which are antifreeze and cooling. The color does not affect their performance. 2. The color is merely a distinguishing factor used by manufacturers and does not indicate any special functions. 3. The reason for the variety of coolant colors is primarily due to the different formulations used by various manufacturers. In terms of composition, ethylene glycol is generally green, propylene glycol is red with a hint of orange, and glycerol is blue. Additionally, to prevent confusion with other liquids and accidental ingestion, many manufacturers add different color formulations for distinction.
I once mixed green and orange coolants when changing the antifreeze, which almost caused a major engine overheating incident. The colors of antifreeze vary significantly: green is typically the old-school inorganic acid salt type, cheaper but needs replacement every two years; orange is Organic Acid Technology (OAT), more durable and can last up to five years; pink or blue might be hybrid HOAT types, commonly found in high-end vehicles. The colors serve as manufacturers' markers to indicate different internal additive compositions—mixing them can trigger chemical reactions forming gels or sediments, clogging cooling passages and impairing performance. Now I strictly use the manual-specified color to avoid issues—safety first.
