The Importance of TEOST MHT and 33C Testing for Engine Oils

The Importance of TEOST MHT and 33C Testing for Engine Oils

In the realm of engine oil additives, ensuring that oils can withstand extreme operating conditions is crucial. Among the various tests that gauge oil performance, the TEOST MHT and TEOST 33C stand out. These tests are essential for evaluating an oil’s resistance to oxidation and deposit formation, which can directly affect engine efficiency and longevity. Despite their importance, passing these tests is challenging, and not all companies can meet these rigorous standards consistently.

The Challenge of TEOST MHT and 33C

The TEOST MHT and 33C tests are designed to predict how engine oil will behave under severe conditions, specifically focusing on deposit formation in critical engine areas.

TEOST MHT simulates the deposit-forming tendencies of oil in the piston ring belt and upper piston crown areas of an engine. Deposits in these regions can lead to significant operational problems and reduced engine lifespan. The test involves exposing a thin film of oil on a test rod to repetitive passages of gases under oxidative and catalytic conditions at a constant temperature of 285°C for 24 hours. This setup mimics the conditions of oil exposure in an engine, including the oxidation process. The TEOST MHT test provides valuable insights into how well an oil can resist deposit formation, which is crucial for maintaining engine cleanliness and performance.

TEOST 33C, on the other hand, is developed to simulate deposit formation in turbochargers and is correlated to field data. This test measures the oil's resistance to higher temperature oxidation phenomena and uses two progressive oxidation zones:

• The 33C Reactor Zone: Where oxidation precursors are formed at engine operating temperatures.
• The Depositor Rod Zone: A high-temperature environment simulating the turbocharger rotor shaft, where the oxidation process and deposit formation are completed.

During the TEOST 33C test, the oil is heated to 100°C in the reactor, exposed to a mixture of moist air and nitrous oxide to mimic the engine crankcase atmosphere. It is then pumped through the casing containing the Depositor Rod, which undergoes cyclic heating between 200 and 480°C to simulate turbocharger temperature changes. Deposits formed on the rod are measured to assess the oil's oxidative resistance and its performance in high-temperature environments.

The Importance of Passing These Tests

Meeting the requirements of these tests is crucial for oils that adhere to API SN specifications. However, not all oils, even from major manufacturers, consistently pass these stringent tests. This makes the successful performance in these tests a significant achievement.

SCT Chemicals: Leading the Way

SCT Chemicals is one of the few companies that have demonstrated exceptional performance by passing both the TEOST MHT and 33C tests. Their additive packages, such as SC13408 for API SN ACEA A3/B4 oils, achieved a deposit level of just 24mg for MHT and 1.9mg for 33C. Treat rate of SC13408 8.5% Similarly, the SC10357 package for API SN ACEA C3 oils passed both tests with a deposit level of only 29mg for MHT and 9mg for 33C. Treat rate SC10357 only 7.7%. These results underscore SCT Chemicals' commitment to delivering high-quality additives that meet and exceed industry standards, ensuring optimal engine performance and protection.

Conclusion

The TEOST MHT and 33C tests are critical in assessing the performance of engine oils under extreme conditions. These tests help predict deposit formation and oxidation resistance, which are essential for maintaining engine efficiency and longevity. With only a few companies successfully passing these rigorous tests, such as SCT Chemicals, it becomes clear that achieving these standards is a mark of excellence in oil additive formulation. For consumers and manufacturers, choosing oils that excel in these tests ensures better engine protection, improved performance, and extended engine life.