Every drive makes the engine heat up. During combustion, parts of the engine can reach temperatures of over 500°C, so a good cooling system is essential for safe operation.
In Pakistan, cooling systems are under even more pressure as summer temperatures regularly exceed 40°C in many cities and can reach 45°C in some areas. Heavy traffic, long idling, dusty roads and constant use of air conditioning cause further stress on the engine.
Unfortunately, many drivers still:
Use only tap water
Coolants mixing
Purchase cheap, low-grade coolant
Ignore the coolant replacement intervals
At first, these errors don’t look harmful, but over time they can result in:
Engine Overheats
Blocked radiator
Formation of rust
Water pump malfunction
Costly engine repairs
Selecting the right coolant will help protect your engine, increase cooling performance and keep your car working well in Pakistan’s tough driving conditions.
What Does Car Coolant Actually Do?
Coolant, also known as antifreeze or radiator coolant, is a specially formulated liquid that circulates through the engine and radiator to regulate temperature. It absorbs heat from the engine and releases it through the radiator before circulating again.
Think of coolant like the sweat system in your body:
Your body sweats to get rid of heat
Your car contains a coolant that removes heat from the engine
Without a coolant the engine would get very hot very quickly.
Most engines run from around 90-105 degrees Celsius today. In many cars, the radiator fans will turn on at about 95 degrees Celsius to keep it safe.
Besides controlling temperature, coolant also:
Stops rust and corrosion
Lubricates water pump
Protects metal parts
fights scale buildup
Prevents freezing in cold weather
Why Choosing the Wrong Coolant Is Dangerous
Many people think coolant is just water with a different color, but modern coolant contains corrosion inhibitors, additives and chemical compounds specifically formulated for automotive cooling systems.
Incorrect coolant may damage important cooling system parts.
1. Overheating
Poor quality or incompatible coolant may not be able to transfer heat efficiently. This is especially dangerous when:
Long traffic jams for…
Driving on a highway
Summer afternoons
Mountain drive
Pakistan’s hot summer temperatures challenge cooling systems.
2. Rust and Corrosion
Plain water and poor quality antifreeze can cause inside corrosion:
Radiator
engine passageways
Pumps (Water)
Heater Core
Eventually, rust particles can clog up the coolant flow and decrease the efficiency of cooling.
3. Water Pump Failure
Coolant also lubricates the seals in the water pump. Poor lubrication can cause a shorter pump life. Water alone does not lubricate properly.
The cost of replacing a damaged water pump can run into thousands of rupees, depending upon the vehicle.
Understand the Different Types of Coolants
Not all coolants are the same. Modern vehicles use different coolant technologies depending on engine design and materials.
IAT Coolant (Inorganic Additive Tech)
IAT coolant is the standard coolant in most older cars.
Features:
Usually green.
Uses silicate additives
Shortened lifespan
Needs replacement often,
Usage:
Older Japanese vehicles
Older local cars
Conventional cooling systems
Lifespan:
Usually 2 years or 40,000 km depending on use and climate.
IAT coolants provide fair protection but break down faster than newer technologies.
OAT (Organic Acid Technology) Coolant
OAT coolant is a modern long life coolant used in many newer vehicles.
Features:
Longer life expectancy
Improved corrosion resistance
Appropriate for aluminum engines
Better high temperature performance
Best For:
Sedans of today
Imported cars
Turbocharged motors
Realistic Lifespan:
Lasts for 5 years or over 150,000 km under the right conditions.
This is one reason why many modern manufacturers suggest OAT coolants for newer engines.
HOAT Coolant (Hybrid Organic Acid Technology)
HOAT combines traditional and modern coolant technologies.
Features:
Strong corrosion protection
Long service life
Balanced performance
Common Usage:
European vehicles
Some Korean cars
Modern hybrid systems
HOAT coolants are designed to provide better compatibility with mixed-metal cooling systems.
Does Coolant Color Matter?
One of the biggest myths in Pakistan is:
“Red coolant is better.”
Or:
“Green coolant is for old cars.”
In reality, coolant color alone does NOT determine compatibility.
Different manufacturers use different dyes for branding purposes.
For example:
Two red coolants may have completely different chemical formulas
A green coolant from one brand may not match another green coolant
Common coolant colors include:
Green
Red
Blue
Pink
Orange
Yellow
Always check:
Manufacturer recommendations
Coolant specifications
Vehicle owner’s manual
instead of relying only on color.
How to Choose the Right Coolant for Your Vehicle
Choosing the correct coolant becomes easy if you follow a few practical steps.
1. Check Your Owner’s Manual
Your owners manual will have the best source for coolant recommendations.
Manufacturers usually indicate:
Coolant technology (IAT, OAT, HOAT)
Mixing ratio.
Variation period
Approved standards
Not following the manufacturer’s recommendations can damage the cooling system over time.
2. Consider Pakistan’s Climate
Challenges for Pakistan’s cooling systems:
High environmental temperatures
Traffic jam
Continuous use of AC
Accumulation of dust
These conditions can increase the risk of overheating.
Good coolant keeps engine temperature steady in extreme weather. In some parts of Pakistan temperatures can rise above 45°C during the peak summer months.
3. Use Quality Coolant
Cheap coolant tends to have poor additives and poor anti-corrosion.
Good coolant may cost a little more up front but it protects expensive parts such as:
Radiator
Water pump
thermostat
Heater core ( copper )
Engine block
Replacing a damaged radiator on a vehicle can be far more expensive than normal maintenance using quality coolant.
Coolant vs Water — Which Is Better?
Many drivers still use plain water because it seems cheaper and easily available.
But plain water creates several long-term problems.
Feature
Coolant
Plain Water
Rust protection
Yes
No
Corrosion inhibitors
Yes
No
High-temperature stability
Better
Weak
Lubricates water pump
Yes
No
Mineral deposits
Low
High risk
Boiling resistance
Higher
Lower
Coolant helps prevent overheating better than plain water alone. A typical 50/50 coolant mixture combined with a pressurized cooling system can raise boiling resistance to approximately 120°C–128°C.
Tap water also contains minerals that can create:
Scale buildup
Radiator blockage
Corrosion inside engine passages
That is why water should only be used temporarily in emergencies.
Can You Mix Two Different Coolants?
Generally speaking , mixing coolants is not recommended .
Coolant formulas contain different additives and chemical packages.
Mixing incompatible coolants can:
Generate sludge
Corrosion protection decreases
Block off radiator passages
Seal and hose damage
Lower the heat transfer efficiency
The colors might look the same, but the chemical formulas are totally different.
If you are changing types of coolant, it is safer to flush the entire cooling system first.
Signs Your Car Needs Coolant Replacement
Antifreeze does not last forever.
Additives lose effectiveness as they degrade over time.
