2015 Peterbilt 579 Oil Capacity & Filter Specs

The 2015 Peterbilt 579, when equipped with the popular PACCAR MX-13 engine, typically requires 11 US gallons (41.6 liters) of engine oil.

Quick Answer

• Oil Capacity: 11 US Gallons (41.6 Liters) - for PACCAR MX-13 engine. Consult your owner's manual for other engine options.
• Recommended Oil Weight: 10W-30 or 15W-40 (depending on ambient temperature and PACCAR recommendations).
• Oil Type Spec: API CJ-4 or API CK-4 (CK-4 is backward compatible and generally preferred).
• Oil Filter OEM Part Number: PACCAR 1935811PE (for PACCAR MX-13)
• Aftermarket Cross-References (PACCAR 1935811PE):
  • Fram: HPX35811
  • Wix: 57920
  • Mobil 1: Consult Mobil 1 catalog for heavy-duty applications as specific cross-references can vary.

Capacity by Engine Option

The Peterbilt 579 in 2015 was available with several engine options. The most common was the PACCAR MX-13, but Cummins engines were also offered. Always verify your specific engine and its required oil capacity with your owner's manual or by checking the engine data plate.

Oil Change Interval

For the 2015 Peterbilt 579, oil change intervals can vary significantly based on engine type, operating conditions, and oil analysis results. Always refer to your owner's manual and follow the recommendations for your specific engine and duty cycle.

• Normal Duty: Typically 30,000 to 50,000 miles or 500 hours, whichever comes first. This can extend to 60,000-80,000 miles or more with oil analysis programs and specific engine/oil combinations.
• Severe Duty: For applications involving heavy loads, frequent idling, extreme temperatures, or dusty environments, intervals may need to be shortened to 20,000-30,000 miles or less.

Regular oil analysis is highly recommended for heavy-duty trucks to optimize oil change intervals and monitor engine health.

Drain Plug Torque

• PACCAR MX-13 Engine Oil Drain Plug Torque: 50-60 ft-lbs (68-81 Nm). Always use a new crush washer or O-ring as specified by the manufacturer to ensure a leak-free seal. Over-tightening can damage the oil pan or plug.

For Cummins engines, consult the specific Cummins service manual for exact torque specifications, as they can vary by model.

How to Change the Oil

Changing the oil on a heavy-duty truck like the Peterbilt 579 requires proper equipment and safety precautions.

1. Preparation: Park the truck on a level surface, engage the parking brake, and allow the engine to warm up slightly, but not be too hot to handle.
2. Locate Drain Plug: Place a large oil drain pan (capacity of at least 15 gallons recommended) under the engine oil pan. Locate the drain plug.
3. Drain Oil: Carefully remove the drain plug, allowing the old oil to drain completely. Inspect the drain plug and replace the crush washer/O-ring.
4. Replace Filter: Locate and remove the old oil filter(s). Apply a thin film of new oil to the gasket of the new filter(s) and hand-tighten them according to manufacturer instructions.
5. Refill Oil: Reinstall the drain plug. Fill the engine with the recommended type and amount of new engine oil. Use a funnel to avoid spills.
6. Check Level: Start the engine and let it run for a few minutes to circulate the new oil. Check for leaks around the drain plug and filter(s). Shut off the engine, wait a few minutes for the oil to settle, and then check the oil level with the dipstick, adjusting as necessary.

Common Issues / Tips

• Oil Analysis: For fleet operators or owner-operators, routine oil analysis is crucial. It helps in determining the optimal oil change interval, detecting potential engine wear, and identifying contaminants before they cause major damage.
• Filter Quality: Always use high-quality oil filters. Heavy-duty diesel engines operate under immense stress, and a good filter is essential for protecting the engine.
• DEF System: The 2015 Peterbilt 579 likely uses a Diesel Exhaust Fluid (DEF) system. While not directly related to oil capacity, ensuring proper maintenance of the DEF system is vital for overall engine health and emissions compliance.
• Consult Manuals: Always refer to your specific truck and engine owner's manual for the most accurate and up-to-date information on capacities, specifications, and maintenance procedures. Heavy-duty truck specifications can vary significantly even within the same model year.

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