TEOST® Trident

Thermo-Oxidation Engine Oil Simulation Test
Test Methods
  • ASTM D6335 | 33C
    (Chinese SH/T0750)
  • ASTM D7097 | MHT®
    (Moderately High Temperature)
  • ASTM D8447 | TEOST Turbo®

The three current TEOST® tests operate under temperatures and environmental conditions identified as significant in internal combustion engines to simulate the oxidation and deposit-forming tendencies of engine oils. Oil samples, treated with catalyst, are pumped over a heated steel Depositor Rod on which deposits form. The weight of the Depositor Rod after the test is subtracted from its pre-test weight and added to the particulate weight collected by filtering the remaining oil. The results are reported in milligrams. 

In the mid-1980s, Savant Labs developed a unique two-stage oxidation/deposition test technique for engine oils formulated for high-temperature performance. Joint cooperation with Chrysler Corporation resulted in a modified, very high temperature cyclic technique successfully applied to oils blended for turbocharger lubrication temperatures. The technique, known as TEOST® 33C, became ASTM D6335, and Savant Labs received a Chrysler Technology Award in 1993.

Additional work proved successful in modifying the TEOST® to measure deposits on a thin-film of circulating oil. This lower, but constant temperature application, correlated to the piston ring belt area of the combustion engine. The TEOST MHT® (Moderately High Temperature) protocol later became ASTM D7097. International engine oil specifications now include both 33C and MHT®.

As engine designs have evolved over the years, particularly turbochargers, the need for an additional modification to the TEOST® platform became evident with the trends in increasing oil change intervals, improved fuel efficiency, and longer residence times for turbocharger cooling. Development began in 2017 on a new lower-temperature, high-duty cycle deposit test to accurately assess deposit formation in modern engines. This technique, known as TEOST Turbo®, became ASTM D8447 in 2022.

  • Adjustable temperature zones and pump speeds.
  • Clear Glass Mantle with MHT® and Turbo® tests for easy viewing of depositor area during the test.
  • Ability to collect the volatilized material for further analysis and investigation.
33C Reference Oils | ASTM D6335MHT® Oils & Catalyst | ASTM D7097TEOST® Calibration OilTurbo® | ASTM D8447

For a complete listing of part numbers and available container sizes of Tannas Reference Oils, please review the Tannas Reference Oils & Catalysts Parts List.

Visit our Certified Reference Materials page to download SDS sheets or Oil Certificates.

Depositor Rods crafted from precision machined steel meet Tannas specifications for exclusive use in TEOST® tests. All rods undergo a rigorous inspection and measurement process prior to acceptance.

Mass Flow Controllers, utilized for all three TEOST® tests, introduce various components to the test oil such as reactive gases and air. The MHT® Mass Flow Controller solely operates with the D7097 test, while the Trident Mass Flow Controller operates with both ASTM D6335, D7097, and D8447 tests.

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TEOST® Trident


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