What is the coolant in a car?

Definition of coolant

Coolant is mostly a 50/50 mix of water and antifreeze. The antifreeze is typically ethylene glycol, which perfectly mixes with water and prevents your engine from getting down below the freezing point and going higher than the boiling point. The water in the coolant is not simple tap water, as tap water contains minerals that can be harmful to your engine. So the coolant manufacturers use deionized or distilled water when producing their pre-diluted coolants.  But if you have a concentrated coolant, then you should add either deionized or distilled water to it to dilute them yourself. 

Key functions of coolant

Coolant helps your engine stay cool in hot weather. It keeps the engine from boiling over and also protects the engine from freezing during the winter. In other words, coolant increases the boiling point and lowers the freezing point of your engine. That's probably why people often group coolant and antifreeze together. 

Other than engine temperature regulation, there is another crucial benefit to coolant: it prevents corrosion of your cooling system. Coolant has a rust inhibitor in it so that something in the water does not eat away into the metals. But there are a variety of inhibitors and, depending on the type, the color of your coolant can differ. You might have seen blue, green, red, or black coolant on the store shelves but they are not always compatible with each other. So to be on the safe side, make sure to get the same type of coolant topped off as the one you have been using.

How to choose the best coolant

Coolant comes in many different colors, often depending on the level of protection. As every component in a car needs to be taken care of, the manufacturers are producing coolant with aluminum, plastic, and rubber protection in it, and thus making their colors more varied. But remember, coolant's key roles are anti-boil, anti-freeze, and anti-corrosion. So no matter how many types of coolants are out there, they all generally do the same thing. The safest choice will be to go with what your car brand recommends. So, look at your owner's manual and get the product you need or simply ask your dealer.

Useful tips for dealing with low coolant and overheating

When your engine overheats from a low coolant level, suddenly adding coolant to the radiator or the coolant reservoir may cause cracks in the engine. To avoid any damage, add coolant slowly in small quantities. Also, do not drive without coolant. It may lead to pump failure and engine seizure, etc.