What kind of oil does a 5.9 Magnum take?
The 5.9 Magnum typically uses 5W-30 or 10W-30 motor oil that meets API service standards and Chrysler guidelines. Always check your vehicle’s owner’s manual for the exact specification for your model and climate.
The 5.9 Magnum is a 360-cubic-inch V8 that powered Dodge Ram pickups, vans, and some Jeep models from the 1990s into the early 2000s. Because oils and required specs evolved over those years, the precise viscosity and specification can vary by model year and driving conditions. Always verify the exact requirement using your VIN and manual or a dealership resource.
Viscosity guidelines
Below are the common viscosity options used in 5.9 Magnum engines, depending on climate and driving demands. Use the grade the factory or manual specifies, and adjust for extreme heat or cold.
- 5W-30: The most common grade for everyday driving across a wide range of climates. Suitable for many 5.9 Magnum applications.
- 10W-30: Often recommended for hot climates or when 5W-30 isn’t available, particularly for older engines or high-mileage vehicles.
- 5W-40: A synthetic option for higher-temperature environments or for engines under heavy towing, where higher oil film strength can help protection.
Note: Always follow the exact viscosity recommended in your owner's manual, and consider OEM guidance if you tow or drive in extreme conditions.
Oil specifications and capacity
In addition to the viscosity, oils should meet certain specification standards and the engine’s capacity should be kept in mind. The typical 5.9 Magnum uses about 5.5–6 quarts of oil with a filter; some engines may require up to 7 quarts when performing a full fill or if the filter is replaced in a certain way. Look for oils that meet the following specs:
- API service category SL/SM/SN or newer, suitable for gasoline engines
- ILSAC GF-4/ GF-5 or GF-6, depending on the oil grade and year
- Chrysler MS-6395 specification (often found on Mopar-approved motor oils), or OEM-recommended equivalent
- Viscosity grade as above (5W-30 or 10W-30 are the most common)
Always verify with your manual or dealer if the engine has any modifications or special towing requirements.
Maintenance tips
These practical steps help ensure you choose the correct oil and maintain engine health:
- Change oil and filter at intervals recommended by the manual, typically every 3,000–5,000 miles for conventional oil and 5,000–7,500 miles for synthetic blends or full synthetic (depending on driving conditions).
- Use a high-quality oil filter and ensure the drain plug is torqued to spec.
- Check oil level regularly and look for signs of contamination or leaks (burning smell, dark oil, metallic debris).
- Consider an oil with a robust additive package for engines with high mileage or heavy towing, if appropriate.
Following these maintenance practices helps maintain engine protection and efficiency for the 5.9 Magnum.
Summary
For a 5.9 Magnum, most applications call for 5W-30 or 10W-30 oil that meets API service standards, with some owners opting for synthetic blends or full synthetic. Look for oils that meet Chrysler MS-6395 or the OEM-recommended specification, and always conform to the viscosity specified in your manual, which may vary by climate and use. Regular oil changes and a quality filter are key to long-term engine health.
