which engine coolant for my car by reg

You can’t reliably pick the exact engine coolant just from your reg (registration) alone without using a dedicated database, but there is a safe way to get the right product and avoid damaging the engine.

Key point

Use a reputable “lookup by reg” or “by vehicle” tool from an oil/coolant manufacturer or big parts retailer, then match the spec on the bottle to your handbook, not just the colour.

How “by reg” coolant finders work

These online tools and store systems link your number plate to:

• Make, model, engine code and year of your car.

• The official coolant specification (e.g. OAT, HOAT, Si-OAT, P-HOAT, OEM spec numbers) the manufacturer requires.

That’s why shops like Supercheap Auto, TotalEnergies and others let you “enter your reg” then show compatible coolant options for your exact vehicle.

Why you must not guess by colour

Colour is not a standard:

• Green is often older IAT coolant; pink, purple, orange, blue are usually various OAT/HOAT types, but brands differ and overlap.

• Mixing incompatible coolants can cause gel-like sludge, blocked passages and expensive damage to the water pump and radiator.

Always check the type and spec code (IAT, OAT, HOAT, Si-OAT, P-HOAT, plus any OEM numbers) on the label matches what your handbook states, even if the colour looks similar.

Step‑by‑step: finding the right coolant by reg

1. Go to a major oil/coolant brand or parts retailer site that supports reg lookup (for example, “What is the correct coolant and antifreeze for my car?” from TotalEnergies, or big chain motor factors).

2. Enter your registration (and country/state if asked) to bring up your vehicle.

3. Select “cooling system” or “antifreeze/coolant” to see the recommended product family and spec for your car.

4. Compare that spec with your owner’s manual; they should match (or exceed) the required standard.

5. Buy a coolant that explicitly states compatibility with that spec (same type: e.g. phosphated HOAT for many Asian cars, silicated HOAT for many modern European cars, etc.).

Extra tips to stay safe

• Never mix unknown old coolant with new: if you’re changing type, do a full flush first.

• If in doubt, ask a garage or dealer to confirm the exact spec using your VIN, which is even more precise than reg.

• Stick with “for all makes/models” universal coolant only if its data sheet clearly covers your car’s required standard, not just “suitable for most cars”.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.