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Frigutec® engine coolants

Frigutec® OAT-Si

Frigutec® OAT-Si a premium class long-life engine coolant concentrate based on 1,2-ethanediol (MEG) with Lobrid technology. This means that Frigutec® OAT-Si combines Organic Additive Technology with mineral inhibitors (silicate).
Frigutec® OAT-Si provides excellent protection for engines against corrosion, overheating and frost. It was developed to protect modern cooling systems in aluminium and aluminium alloy combustion engines. Frigutec® OAT-Si is free from nitrites, amines, phosphate and the harmful borate. Frigutec® OAT-Si also offers excellent long-term protection. We recommend changing the coolant after 6 years or after 250,000km for passenger cars and at 500,000km for commercial vehicles (whichever is reached first).

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Product details


Frigutec® OAT-Si offers the user the following advantages:

  • Outstanding long-term corrosion protection
  • Excellent protection against thermal stress
  • Excellent long-term stability
  • Excellent silicate stability
  • Excellent frost protection
  • Excellent sealing and material compatibility
  • Excellent economy due to special long-term protection
  • Analyses and quality controls
  • Flexible quotation
  • Weekly, monthly, quarterly and seasonal prices possible

Standards and OEM recommendations

Frigutec® OAT-Si exceeds the requirements of the following coolant standards:

  • ASTM D3306
  • ASTM D4985
  • ASTM D6210
  • BS 6580:2010
  • AFNOR NF R15-601 as of November 2020
  • SAE J1034
  • CUNA NC 956-16
  • Önorm V5123 (except RA)
  • UNE 26-361-88
  • JIS K 2234:2018

Frigutec® OAT-Si has no manufacturer’s approvals. However, we recommend the use of Frigutec® OAT-Si for a number of OEM standards, which we will be happy to send you together with a quotation. Below are some examples:

  • VW Group TL 774-G (G12++)
  • Daimler/Mercedes-Benz 325.5 and 325.6
  • MAN 324 Type Si-OAT
  • MTU MTL 5048
  • Liebherr Minimum LH-01-COL3A
  • Deutz DQC CC-14
  • Cummins CES 14603


Frigutec® OAT-Si offers outstanding year-round protection against frost and corrosion.
Frigutec® OAT-Si Concentrate must be diluted with water before use! We recommend a mixing ratio of 1:1 in volume with demineralised or distilled water. Under no circumstances should Frigutec® OAT-Si be used with less than 33 vol.% or more than 60 vol.%.

Miscibility with other engine coolants

Frigutec® OAT-Si concentrate only works optimally if you drain and rinse the entire cooling system and refill it completely with Frigutec® OAT-Si mixed with distilled water in a 1:1 ratio.
In principle, Frigutec® OAT-Si can be mixed with all commercial engine coolant agents based on 1,2-ethanediol (MEG) with organic additives. However, each manufacturer has found and tested a specially optimised composition of inhibitors which, when mixed with other radiator antifreeze agents from other manufacturers, still work well, but no longer as optimally as Frigutec® OAT-Si alone.
In the event of a warranty claim, it is often impossible to assign the cause that triggered the warranty if several different makes have been used.
Therefore, we recommend the use of Frigutec® OAT-Si only.

Physical and chemical properties

We will be happy to inform you personally about the physical and chemical properties of our coolants. We look forward to your enquiry.

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