The 2008 Dodge Ram 1500 with the 5.7L Hemi generally uses 5W-20 motor oil as the standard grade; 5W-30 can be used in hot climates or when carrying heavy loads. The oil should meet Mopar MS-6395 and API SN (or newer) specifications, and the engine takes about 7 quarts with a filter.
In practice, your choice between conventional and synthetic oil depends on driving conditions and warranty considerations. Synthetic oils offer better protection and longer change intervals, while conventional oils are acceptable if changed on schedule and you stay within the recommended viscosity range.
The following options cover the recommended oil grades and specifications for this engine. Be sure to choose an oil that meets the Mopar MS-6395 specification and is API certified.
- 5W-20 motor oil (synthetic or conventional) that meets Mopar MS-6395 and API SN or newer.
- 5W-30 motor oil that also meets Mopar MS-6395 and API SN or newer (acceptable in hot climates or with heavy towing/loads).
- Fully synthetic is generally preferred for better engine protection and longer drain intervals, though conventional 5W-20 or 5W-30 is acceptable if you follow the recommended change intervals.
- Always confirm oil meets the specification listed in the owner's manual and use the correct oil filter for the 5.7L Hemi.
In practice, for most owners, 5W-20 is the standard recommendation, with 5W-30 available for extreme heat or demanding use. Use an oil that meets Mopar MS-6395 and ensure you adhere to the vehicle’s maintenance schedule.
Oil capacity and change interval
The 5.7L Hemi in the 2008 Ram typically holds about 7 quarts (roughly 6.6 liters) of oil with a filter installed. Oil changes are commonly recommended every 3,000–5,000 miles with conventional oil and about 5,000–7,500 miles with synthetic oil, depending on driving conditions and manufacturer guidance. Always refer to the owner's manual for the exact intervals and follow your driving profile (city, highway, towing, temperature) to determine the optimal schedule.
Summary
For a 2008 5.7L Hemi, use 5W-20 as the standard viscosity (5W-30 is acceptable in hot climates or heavy-use scenarios) and ensure the oil meets Mopar MS-6395 and API SN or newer. Plan to use about 7 quarts with filter and follow the appropriate change interval based on whether you use conventional or synthetic oil. Always verify the latest specifications in the owner’s manual and consult a trusted service professional if you’re unsure.