Alternative to FROSTOX HT-12

Many vehicles, trucks, and motorcycles require FROSTOX HT-12 as their coolant.

You can buy this from a dealer, but we also wanted to explain why Valvoline Zerex G40 is a suitable and easier-to-get alternative for FROSTOX HT-12.

When buying alternatives, it’s easy to get stuck in the rabbit hole of asking internet friends for “what coolant to use”. Opinions are plentiful but they can really mislead you. So that’s why it’s important to check spec sheets to make sure you’re not being led astray.

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The product FROSTOX HT-12 is made by German company Haertol GMBH.

Per their data sheet for the product, FROSTOX HT-12 is a “monoethylene glycol based premium antifreeze”. It is based on “Si-OAT” corrosion protection, “contains no 2-ethylhexanoic acid”, and “contains no nitrites, amines, phosphates, or borates”.

Frostox HT-12 product information sheet

A few words on the spec for FROSTOX HT-12.

  • Monoethylene glycol is the same as ethylene glycol. It’s sometimes termed monoethylene glycol to distinguish it from di-ethylene glycol, which is a by-product of making any monoethylene glycol. (Ethylene glycol is the most common antifreeze protector for vehicles, and the only one any manufacturer recommends.)
  • Si-OAT is a variant on OAT (Organic Acid Technology) coolants. OAT coolants don’t contain any minerals that can attack the cooling systems, i.e. pure OAT coolants don’t contain silicates, phosphates, nitrites, amines, or borates.
  • There are variants like P-OAT (that contain phosphates) and Si-OAT (which contain silicates) that have one of the above minerals. Si-OAT is an example of this.

So basically, FROSTOX HT-12 is a Si-OAT coolant that’s based on ethylene glycol.

A few vehicles FROSTOX HT-12 is recommended for include:

  • The 2021+ BMW M 1000 RR
  • Other 2021+ BMW sport motorcycles
  • 2018+ BMW cars
  • 2018+ Mini cars
  • Toyota Supra 2019+

About Valvoline Zerex G40

Valvoline Zerex G40 is another Si-OAT coolant, in other words, an OAT coolant that does have some silicates.

Per their product information sheet (direct link), Valvoline Zerex G40 is also an ethylene glycol-based coolant that contains no phosphates, borates, nitrites, or amines.

Valvoline Zerex G40 coolant specs

Note that Zerex G40 is likely to come in a different colour to FROSTOX HT-12. This doesn’t matter; coolants are dyed for branding purposes.

What happens if you use the “wrong” coolant?

Many people just put “any old green/pink/blue stuff” into their vehicle and forget about it.

(Note that color of coolant is nearly meaningless technically, and it’s possible for two similar colour coolants to have different components, like Coke and Pepsi for example. Coolants are colored so within a brand you can be fairly sure that pink = pink, and so on.)

If you use any old ethylene glycol-based coolant, your motorcycle, car, or jetski is likely to be “fine” — for a while, maybe even 10s of thousands of kilometres or miles.

However, if your coolant contains additives that aren’t good for your cooling system components (the water pump and radiator being common failing points), you may find that your water pump may fail or your radiator may start leaking.

So if your coolant is a Si-OAT or HOAT or OAT coolant especially, don’t use one in that has additives that might damage your cooling system.

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