Mack T11 Analysis Sept 9 2005 Mack T11

Mack T-11 Analysis Sept 9, 2005

Mack T-11 Test Analysis • • The current T-11 test method provides protection from oils with excessive soot thickening The current reference oil 820 -2 is a failing oil Some oils which give thickening rates similar to 820 -2 can pass the T-11 test. The slope of the viscosity increase versus soot relationship can provide additional verification of oil performance

Mack T-11 Test Analysis • • The slope of the viscosity versus soot relationship was determined for several oils Results from 180 through 252 hours were plotted vs. the soot The natural log of the viscosity increase and the absolute viscosity measured by the rotational method at 100 C (decreasing) were both evaluated A linear least squares regression line was fitted to the data and the slopes of these lines were compared

Log of the Kinematic Viscosity Increase Reference tests on 820 -2

Mack T-11 Tests Passing and Failing Oils (Good Oil >7. 6% soot @ 12 c. St, Poor Oil = 4. 8% soot @ 12 c. St)

Mack T-11 Tests Passing and Failing Oils (Good Oil >7. 6% soot @ 12 c. St, Poor Oil = 4. 8% soot @ 12 c. St)

Mack T-11 Tests Passing Oils (Oil A = 6. 14% soot @ 12 c. St, Oil B = 6. 83% soot @ 12 c. St) Oil A Oil B

Mack T-11 Tests Passing Oils (Oil A = 6. 14% soot @ 12 c. St, Oil B = 6. 83% soot @ 12 c. St) Oil A Oil B

Slope of the Natural Log of the Kinematic Viscosity Increase with Soot • Poor Oils > 0. 8 • Marginal Oils 0. 5 – 0. 8 • Good Oils < 0. 5 • Continue the current Pass/Fail Requirement At 12 c. St