SwRI: The Mack T-11 evaluates soot handling performance of lubricating oils in diesel engines with cooled EGR, specifications Mack EO-N Premium Plus, Mack EO-N Premium Plus 03, API CI-4 Plus.

	The Mack T-11 procedure evaluates soot handling performance

The Mack T-11 procedure evaluates the soot handling performance, as measured by viscosity increase, of lubricating oils operating in diesel engines equipped with cooled exhaust gas recirculation. The evaluation is part of specifications:

• Mack EO-N Premium Plus

• Mack EO-N Premium Plus 03

• API CI-4 Plus

The field service simulated includes:

• Heavy-duty diesel engines

• Stop-and-go operation

• High-soot loading

Mack T-11 Equipment and Procedure

The engine is a Mack E-TECH V-MAC III, electronically controlled fuel injection with six electronic unit pumps, using 2002 low-swirl cylinder heads. The engine is an open-chamber, in-line, six-cylinder, four-stroke, turbocharged, air-cooled compression ignition engine. The bore and stroke are 124 by 165 mm (4-7/8" X 6-1/2"), and the displacement is 12 L (728 in³). The engine uses cooled exhaust gas recirculation to meet 2004 emissions regulations.

The Mack T-11 procedure runs for 252 hours and includes a break-in or a pretest oil flush sequence unless the engine build life has been exhausted, at which point, the engine is torn down for rebuild. Controlled parameters include:

• Speed

• Fuel flow

• Intake CO₂

• Inlet manifold temperature

• Coolant out temperature

• Fuel temperature

• Oil gallery temperature

• Intake air temperature

Mack T-11 Evaluation Results

At the end of the procedure, oil filter plugging is examined. Oil samples are taken every 12 hours and analyzed for soot content and viscosity.

Pass/fail criteria include:

• Soot at 12 cSt viscosity increase

• MRV viscosity (cP)

All operationally valid procedures should produce a TGA soot level of:

• 2.75 ± 0.25 at 96 hours

• 5.50 ± 0.35 at 192 hours

• 6.53 ± 0.44 at 228 hours

A lab should terminate a procedure that has missed any soot windows; such tests are considered operationally invalid. Additionally, all operationally valid procedures shall not exceed an oil consumption of 65.0 g/h.

For more information about the Mack T-11 procedure capabilities at Southwest Research Institute (SwRI) or how you can contract with SwRI, please contact Ryan Johnson at rjohnson@swri.org or (210) 522-2892.