Question 1

What is the difference between antifreeze and coolant?

Accepted Answer

Antifreeze is the concentrated glycol product; coolant is what you put in the engine, which is antifreeze already mixed with water at the correct ratio plus the corrosion inhibitor package. In practice the words are used interchangeably, and the important thing is the specification and the freeze point, not the label wording. Most products sold today are ready-to-use premixed coolant.

Question 2

Can I use water instead of coolant in an emergency?

Accepted Answer

Yes, in an emergency, to get the vehicle home. Water alone has no corrosion inhibitors, boils at a lower temperature than a glycol mix and can freeze and crack the block. Drain and refill with the correct premixed coolant as soon as possible.

Question 3

Does coolant colour tell me the technology?

Accepted Answer

No. Colour is only a dye chosen by the blender. Green is traditionally associated with IAT, pink and red with OAT and orange with Dex-Cool style chemistry, but nothing enforces this and many products break the convention. Always identify coolant by its specification or OEM approval, never by colour.

Question 4

What is the difference between OAT, HOAT, IAT and Si-OAT?

Accepted Answer

They are different inhibitor chemistries. IAT uses inorganic salts and lasts about two years. OAT uses organic acid carboxylates and lasts five years or more but protects more slowly. HOAT combines OAT chemistry with a small amount of silicate or nitrite for faster initial protection. Si-OAT pairs silicate with OAT and is common in European specifications because it protects aluminium from the first minute.

Question 5

What is a borate-organic hybrid coolant?

Accepted Answer

A formulation that uses borate as the primary corrosion inhibitor working alongside organic acids. Borate gives very stable pH buffering, so the coolant resists acidification, depletes slowly and produces little deposit. It is a common choice for Asian aftermarket production and for hot-climate markets.

Question 6

Why does my coolant need a high boil point in a hot climate?

Accepted Answer

Because boil-over, not freezing, is the failure mode in hot climates. In slow traffic there is little airflow through the radiator, coolant temperature climbs, and if it exceeds the boiling point at system pressure it erupts into the overflow bottle. A higher boil point, combined with a pressure cap that still holds its rating, is what prevents that.

Question 7

Does more glycol always mean better protection?

Accepted Answer

No, and this surprises people. Freeze point improves as you add glycol up to about 70 percent by volume, then gets worse again — neat glycol freezes near minus 13 degrees Celsius. Above roughly 70 percent you also reduce heat transfer efficiency. Mix to the ratio the vehicle maker specifies.

Question 8

What does the pressure cap have to do with coolant?

Accepted Answer

Everything. Every 1 psi of system pressure raises the boiling point of a 50 percent glycol mix by about 1.7 degrees Celsius. A typical 15 psi cap therefore adds around 25 degrees Celsius of boil-over margin. A cap that no longer holds pressure removes that protection silently, which is why it should be replaced on schedule.

Question 9

How do I choose the right coolant for a tropical market?

Accepted Answer

Prioritise boil-over margin and corrosion protection over freeze protection. Look for an atmospheric boil point of 104 degrees Celsius or higher, genuine glycol content rather than dyed water, pH between 8.0 and 9.5, reserve alkalinity of at least 10 millilitres, chloride at or below 25 mg/kg, and documented ASTM D1384 and D4340 corrosion test passes.

Question 10

What coolant grades should a distributor stock?

Accepted Answer

It depends on your vehicle parc. A typical tropical distributor does well with one 0 degrees Celsius high-boil-point coolant covering most local demand, plus a minus 25 degrees Celsius grade for inland or highland areas and a premium long-life option. Cold-climate distributors need minus 37 and minus 45 degrees Celsius grades. Keep the range short and go deep rather than stocking many near-identical SKUs.

Question 11

What specifications should I ask a supplier for?

Accepted Answer

Freeze point, atmospheric boil point, pH, reserve alkalinity, density, chloride content, ash content, ASTM D1881 foaming, ASTM D1384 glassware corrosion and ASTM D4340 cast aluminium heat-rejection results, plus a Certificate of Analysis for the actual production batch. A supplier who cannot provide these for a specific batch should not be supplying professional coolant.

Question 12

Is a cheaper coolant a false economy?

Accepted Answer

Usually. The cost of coolant is a small fraction of the cost of a radiator, water pump or head gasket. Products priced close to bottled water typically contain little or no glycol and a weak or absent inhibitor package, so they fail to prevent the corrosion and scale that lead to real engine damage.

Question 13

Do you supply OEM and private label?

Accepted Answer

Yes. We blend to your specification within a technology family, print your artwork and cartons, and supply the documentation package including SDS per formulation and COA per batch. Label-only changes are the fastest route to market; custom bottles require higher minimum order quantities because of tooling.

Question 14

What is the minimum order quantity for private label?

Accepted Answer

A private label on a standard bottle with your own label typically starts from one pallet. A new label size needs around 3,000 to 5,000 pieces because of print setup. A custom bottle mould requires roughly 20,000 to 30,000 pieces to amortise the tooling. A custom formulation within a technology family usually needs 2,000 to 5,000 litres.

Question 15

How long does a coolant order take to produce and ship?

Accepted Answer

Standard production lead time is 3 to 10 days depending on specification and packaging, with new label artwork adding a little longer. Sea freight from Guangzhou to Southeast Asian ports is typically short, and we provide the full export documentation set including commercial invoice, packing list, SDS, COA and certificate of origin.

Question 16

How often should coolant be changed?

Accepted Answer

It depends on the technology, the concentration, the duty cycle and the system condition. As a starting point: IAT about two years, OAT and hybrid packages three to five years, heavy-duty long-haul trucks one to two years, and severe duty such as mining or generator sets annually. Always follow the vehicle maker's interval where it is more conservative, and test rather than guess.

Question 17

Why has my coolant turned brown?

Accepted Answer

Brown means iron oxide is forming faster than the inhibitor can prevent it. The usual causes are a depleted inhibitor package past service life, over-dilution with plain water, the wrong chemistry for the metals in the system, or air being drawn in through a failing hose, cap or head gasket.

Question 18

Why has my coolant turned milky or creamy?

Accepted Answer

Milky coolant almost always means oil or combustion gas has entered the cooling system, typically through a failed head gasket, a failed oil cooler or a split transmission cooler inside the radiator. This is a mechanical fault, not a coolant problem, and changing the coolant will not fix it.

Question 19

Can I mix two different coolants?

Accepted Answer

Within the same technology family, topping up between compatible products is usually acceptable. Across families it is not: mixing an OAT coolant with a silicate-heavy IAT product can cause silicate to drop out of solution as a gel or sediment that clogs the radiator core and heater matrix. If you do not know what is in the system, flush and refill rather than top up.

Question 20

My coolant level keeps dropping but I see no leak. Why?

Accepted Answer

Common causes are a failed pressure cap letting coolant escape as vapour, a small head gasket leak passing coolant into combustion, a leaking heater matrix that shows up as a sweet smell and a misted windscreen, or an airlock causing the level to move between hot and cold readings. Pressure-test the system and check for combustion gases before assuming you need a new radiator.

Question 21

The heater blows cold but the engine temperature is normal. What is wrong?

Accepted Answer

Most often the heater matrix is airlocked or partially blocked. Airlocks follow a coolant change where the system was not purged properly; blockage usually follows mixed coolants, a depleted inhibitor package or stop-leak products. A blocked matrix often indicates sediment elsewhere in the system too.

Question 22

Do stop-leak products work?

Accepted Answer

They can temporarily seal a small leak, but they frequently cause more expensive problems by plugging heater matrices and narrow cooling passages. Use them only as a short-term emergency measure and flush the system properly once the real repair is done.

Question 23

How do I check the coolant concentration?

Accepted Answer

Use a refractometer rather than a float-type hydrometer. A refractometer reads the freeze point from a few drops and is not distorted by dye or by dissolved corrosion products the way a float gauge is. Check at every service and record the reading, because an upward drift means someone is topping up with water.

Question 24

What is the HS code for engine coolant and antifreeze?

Accepted Answer

The six-digit HS classification for anti-freezing preparations is 3820.00, which is common across World Customs Organization member countries. Beyond six digits, national tariff codes apply and your customs broker should confirm the final code against the actual formulation and retail packaging.

Question 25

What documents come with a shipment?

Accepted Answer

Commercial invoice, packing list matching the carton structure, safety data sheet for each formulation, Certificate of Origin, and a Certificate of Analysis for the specific production batch showing freeze point, boil point, pH, density and reserve alkalinity. Third-party test reports are available where a national standard or approval is claimed.

Question 26

Is coolant classified as dangerous goods for shipping?

Accepted Answer

Ethylene glycol coolant is usually not classified as dangerous goods for transport, but national rules vary and should be checked. The product most likely to be regulated in this category is aerosol anti-rust or penetrating spray, which is typically UN1950 Aerosols, Class 2.1, and is subject to limited quantity provisions.

Question 27

Can you produce labels in my language?

Accepted Answer

Yes. We print in the language your market requires and can include the specification statement, safety pictograms, net content and batch coding your regulations demand. We will ask you to confirm any local registration or labelling requirements, since the regulatory position sits with you as the brand owner.

Question 28

Does each product have its own SDS?

Accepted Answer

Yes, each formulation has its own safety data sheet in the GHS sixteen-section format. A single generic sheet covering a whole range is not sufficient for customs clearance or for your customers' own compliance obligations.

Question 29

What shelf life should I expect?

Accepted Answer

Coolant and brake fluid typically carry a three-year shelf life when unopened and stored away from direct sunlight. Diesel exhaust fluid is shorter, around twelve to eighteen months when kept between 0 and 30 degrees Celsius, because urea degrades faster in heat. Always check the remaining shelf life on arrival.

Coolant questions, answered properly

Coolant basics

Choosing and buying

Maintenance and troubleshooting

Export, compliance and documentation