The PACCAR MX-13 is a robust 12.9-liter inline 6-cylinder diesel engine designed for heavy-duty trucks, including Peterbilt and Kenworth models. Known for its durability, fuel efficiency, and long service intervals, the MX-13 is widely trusted in the commercial trucking industry. A key component of its performance is proper engine lubrication, which starts with knowing the exact engine oil capacity.
PACCAR MX-13 Engine Oil Capacity
The total oil system capacity of the PACCAR MX-13 engine is 42 U.S. quarts, which is approximately 40.0 liters. This capacity includes the oil held in the engine sump (oil pan) and the oil required for both the full-flow and centrifugal oil filters.
This amount ensures that all moving parts are adequately lubricated, reducing wear and improving overall engine performance.
Best Engine oil for PAACAR MX-13
1. Mobil Delvac 1300 Super SAE 15W‑40
A popular synthetic-blend diesel engine oil, Mobil Delvac 1300 Super, meets API CK‑4, CJ‑4, CI‑4 PLUS, CI‑4, and CH‑4 service categories. It provides excellent soot and viscosity control, outstanding oxidation resistance, and reduced oil consumption, ideal for heavy-duty MX‑13 applications.
2. Chevron Delo 400 XLE Synthetic‑Blend SAE 15W‑40
The successor to the Delo 400 SDE, this synthetic blend meets API CK‑4 and works well in PACCAR MX‑13 engines. Chevron touts its ISOSYN® advanced additive technology, delivering longer drain life, strong oxidation stability, and enhanced component protection in modern emission‐compliant engines.
3. Shell Rotella T6 Full Synthetic 10W‑30
This full synthetic oil is tailored for newer low-viscosity applications like the MX‑13, especially when fuel economy and cold-start performance are priorities.
Rotella T6 10W‑30 features Triple Protection Plus technology, offering enhanced wear protection, deposit control, and improved fuel efficiency, up to ~2% gain versus 15W‑40 oils. It meets both API CK‑4 and API SN specifications, making it suitable for mixed fleet use.
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Recommended Oil Type and Viscosity
PACCAR recommends using SAE 10W-30 engine oil that meets the API CK-4 or CJ-4 classification. This viscosity is suitable for most ambient temperature conditions and ensures consistent performance.
For colder climates where temperatures drop below -15°C (5°F), SAE 5W-30 oil is acceptable, provided it also meets the required API standards.
In warmer climates or under high-load conditions, 10W-40 or 15W-40 may also be used if they meet the correct specifications.
PACCAR does not recommend the use of aftermarket oil additives, as they can interfere with the chemical balance of the engine oil and reduce its effectiveness.
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Oil Change Procedure and Best Practices
Changing the oil in the MX-13 engine requires attention to detail and adherence to recommended procedures to maintain optimal engine health. Below is a basic step-by-step process for performing a complete oil change:
1. Warm Up the Engine
Run the engine to bring it up to normal operating temperature. This helps the oil flow more easily during draining.
2. Drain the Oil
Park the truck on level ground, shut off the engine, and wait 15 minutes for the oil to settle. Remove the oil drain plug and allow the oil to drain completely.
3. Replace Oil Filters
Remove and replace both the full-flow and centrifugal oil filters. Always lubricate the O-rings of the new filters before installation and tighten to the manufacturer’s torque specification.
4. Reinstall Drain Plug
Ensure the drain plug is cleaned and torqued properly before proceeding with the refill.
5. Refill with Fresh Oil
Add approximately 42 quarts of new engine oil. After refilling, start the engine and let it run for a few minutes to circulate the oil.
6. Check Oil Level
Turn off the engine, wait about 15 minutes, then check the oil level using the dipstick. Add oil if necessary to bring the level to the full mark.
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Service Intervals and Maintenance Schedule
Service intervals for oil changes depend heavily on how the engine is used. Below are the general guidelines:
- Line-Haul Operations (less than 20% idle time, fuel economy above 6 mpg, under 80,000 lbs gross vehicle weight):
- Oil and filter changes are recommended every 50,000 miles.
- Vocational or Severe Duty (high idle time, frequent stop-and-go, heavy loads):
- Oil changes are recommended every 30,000 miles.
- Engines Running on Biodiesel (B6 to B20 blends):
- PACCAR recommends shortening oil change intervals, typically around 40,000 kilometers (about 25,000 miles) or every six months, whichever comes first.
These intervals help ensure the oil remains effective in lubricating and cooling the engine, particularly under demanding conditions.
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Importance of Correct Oil Level
Maintaining the proper oil level in the PACCAR MX-13 engine is crucial for the following reasons:
- Overfilling the oil can lead to aeration, crankcase pressure build-up, and potential oil leaks.
- Underfilling can result in insufficient lubrication, low oil pressure, and engine wear.
- The range between the low and full marks on the dipstick represents about 6.3 quarts (approximately 6 liters), so accurate measurement is essential.
Always allow oil to settle before checking and topping up. This helps ensure that the reading reflects the actual oil level in the crankcase.
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FAQs
How much oil does a PACCAR MX-13 take?
The PACCAR MX-13 engine has a total oil capacity of 42 U.S. quarts, which is approximately 40 liters. This includes oil held in the engine block, oil pan, and both oil filters (full-flow and centrifugal). Always check the dipstick after filling to confirm the level is at the full mark.
How many liters is a PACCAR MX-13 engine?
The PACCAR MX-13 engine has a displacement of 12.9 liters. It is an inline 6-cylinder diesel engine designed for heavy-duty use in commercial trucks like Peterbilt and Kenworth.
How many oil filters does a PACCAR MX-13 have?
The PACCAR MX-13 engine uses two oil filters:
- A full-flow oil filter
- A centrifugal oil filter
Both filters should be replaced during each oil change to ensure proper lubrication and to prevent oil contamination.
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How much oil does a Peterbilt PACCAR engine hold?
A Peterbilt truck equipped with a PACCAR MX-13 engine holds approximately 42 quarts (40 liters) of engine oil. This capacity may vary slightly depending on the model year and oil pan design, but 42 quarts is the standard full system capacity.
How long does a PACCAR MX-13 engine last?
With proper maintenance, the PACCAR MX-13 engine can last over 1,000,000 miles. Regular oil changes, proper filter replacements, and adherence to service intervals significantly contribute to engine longevity.
How much oil does a PACCAR TX-12 take?
The PACCAR TX-12 is an automatic transmission system, not an engine. Its oil capacity varies by configuration, but typically it holds around 19 to 22 quarts of transmission fluid. Always refer to the specific transmission manual for exact capacity and fluid type.
Final words
The PACCAR MX-13 engine is built for high performance and long service life, but it requires precise maintenance.
Using the right oil type, adhering to recommended service intervals, and following best practices during oil changes will ensure that your MX-13 runs efficiently for hundreds of thousands of miles.
Regular maintenance is not just good practice, it’s a key part of maximizing uptime and profitability in any trucking operation.
