The TEOST 33C test simulates the effect of engine operating conditions on the oxidation and deposit-forming tendencies of engine oils, especially in the high temperature Turbocharger area. The TEOST MHT test simulates similar effects and conditions found in the ring belt and piston ring areas of the engine.

Oil samples treated with catalysts are pumped over a heated 33C Depositor Rod or a coiled MHT 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 oil remaining. The results are reported in milligrams.


Test Methods

ASTM D6335   |   Dual/33C Model  (Chinese SH/T0750)
ASTM D7097   |   MHT Model (Moderately High Temperature)