The Ultimate Coolant Color Guide

Here’s a fun fact: antifreeze starts out colorless.

All the green, orange, red, pink, amber, and blue coolants you see on the shelves are dyed. Coolant manufacturers don’t add color to their antifreeze just to make it look pretty though. They do it for several important reasons

As a consumer, you should pay attention to the color of the coolant you choose because the wrong color may shorten your engine’s lifespan.

Why Brands Add Dye To Antifreeze

  • To help consumers differentiate one brand from another
  • To distinguish one brand’s coolant formula from the others
  • To make it easier to detect the amount of coolant under the hood

There’s no universal color guide to coolants, so we're here to help you figure out which coolant color is right for you.

The short answer is it depends on the year, make, and model of your car. Read on for the long answer.

Three Types Of Coolants

There are three common types of coolants available in the market:

  1. Inorganic Acid Technology (IAT): This old-fashioned green coolant used for decades is still around because some older cars require it. It contains chemicals that prevent copper brass, cast iron, and aluminum cooling system components from deteriorating. This type of coolant is not recommended for newer cars.
  2. Organic Acid Technology (OAT): Usually orange or yellow, this type of coolant lasts longer and is used in some newer engines where metal protection isn’t required. It is propylene glycol-based and does not contain silicates or phosphates. Because of that, OAT coolants act slow and don’t protect exposed metal as much as IAT coolants do. GM’s DexCool is a leading brand for OAT coolants and comes in an orange color.
  3. Hybrid Organic Acid Technology (HOAT): Many auto manufacturers dislike the fact that OAT coolants don’t protect exposed metal as well as IAT coolants do, but they still like that OAT coolants last longer, are safer to use, and are more environmentally friendly. They came up with a solution: HOAT. It’s a hybrid of IAT and OAT that’s basically OAT coolant with a small number of silicates. It contains the best of both worlds. This type of coolant is marketed under several different names, the most common ones being:

    • G-05 (most European auto manufacturers)
    • G-11 or G-12 (Volkswagen and Audi)
    • Global (most coolant manufacturers)

How To Know Which Type Of Coolant To Use In Your Car

With all the types of coolants available, consumers may be confused as to which color or formulation they’re supposed to put into their car. Adding to the confusion is the fact that Asian, European, and American auto manufacturers each have their own preferred chemical makeup to maximize their engines’ reliability and performance.

green coolant

Photo credit: EvelynGiggles

The manufacturer of your car requires a certain type of coolant for a reason. Their recommended coolant has the right combination of chemicals that will prolong the life of the engine made specifically for your car.

To find out which type of coolant your manufacturer requires, check the owner’s manual. If it recommends a certain brand, go the safe route and get that brand even if it costs a little more than the others.

Green            IAT Pre-1994 GMs
Pre-2001 Chryslers & Fords (except some '99 models)
Orange OAT or HOAT Post-1995 GMs
Post-2012 Chryslers & Fords
Amber OAT or HOAT Post-2002 Chryslers & Fords
Blue OAT or HOAT Select 1999 Fords
Pre-2014 Volvos
Post-2008 Teslas
Pink HOAT Post-2005 Audis, Volkswagens, & Porsches
Post-2014 Jaguars & Land Rovers
Red HOAT Toyotas, Lexuses, & Scions
Purple HOAT 1997-2013 Jaguars & Land Rovers
2002-2011 Saabs

*This is not a definitive guide. Please refer to your owner's manual for the correct type of coolant for your car.

Why You Should Never Mix The Coolants

Each type of coolant has its own formula made specifically for certain cars. Adding the wrong kind of coolant or topping off the reservoir with a different kind of coolant will affect the engine in a variety of ways.

For example, adding an OAT coolant to an older engine that requires the standard IAT green coolant will dilute the stuff the engine really needs – phosphates and silicates. As a result, the metal in your engine won’t get the protection it needs.

Finally, Remember To Flush Your Coolant

Don't forget to flush. This is an important step in auto maintenance. We talk about when to do it in this blog post.