Abstract: The Dry-TOST simulation tests to investigate the oxidation life and sludge formation of four turbine oils were conducted. The results indicate that the oxidation life of sample A is the longest (1 700 h), while the sludge is the most (1 358 μg/g); the oxidation life of oil B is the next (1 512 h)，the sludge is 250 μg/g, but still surpass 100 μg/g standard; the third one is oil C with 1 300 h life and 58 μg/g sludge; the sludge of oil D is the least, only 22 μg/g but the oxidation life is the shortest (336 h). Only sample C is compliant with Mitsubishi MS04-MA-CL002 for the requirement of oxidation life and the sludge formation.

Key words: turbine oil, sludge, oxidation life, oxidation test