Understanding the 2018 Ram 1500 oil capacity is essential for maintaining the peak performance and longevity of one of America’s most capable full-size trucks. The 5.7-liter Hemi V8, the standard powerhouse under the hood, requires a specific volume of lubricant to ensure proper circulation, cooling, and protection against wear. For owners performing their own maintenance or simply curious about their vehicle's specifications, knowing the exact capacity prevents under-filling, which leads to premature engine damage, and over-filling, which can cause pressure leaks and catastrophic failure.
Factory Fill Specifications
When the 2018 Ram 1500 rolls off the assembly line, the factory fill capacity is standardized at approximately 6.4 quarts for the base 5.7-liter Hemi engine. This figure represents the total amount of oil required to fill the crankcase, filter, and associated passages to the correct level. Always verify this number in the owner’s manual specific to your vehicle identification number (VIN), as configurations with different oil filter placements or transmission types can cause slight variations in the total volume needed for a complete system refresh.
Factors Influencing Capacity
While the engine itself dictates the base oil capacity, several variables can alter the final amount of oil required for a change. The type of oil filter used plays a significant role; some high-performance filters hold more oil internally than standard units, effectively increasing the total system volume. Furthermore, if the transmission fluid is being changed simultaneously, the addition of ATF to the torque converter adds several quarts to the overall fluid requirement for the service, pulling the total volume well above the 6-quart baseline.
Recommended Oil Type and Weight
The 2018 Ram 1500’s 5.7-liter Hemi engine is engineered to perform optimally with 5W-20 synthetic blend or full synthetic motor oil. This specific viscosity is critical for the variable valve timing (VVT) system and the Multi-Displacement System (MDS), allowing the engine to switch cylinders off during cruising without sacrificing responsiveness. Using a heavier oil, such as 10W-30, is generally discouraged as it may hinder the MDS’s ability to engage and can lead to decreased fuel economy and increased wear on the valvetrain.
Step-by-Step Oil Change Procedure
A proper oil change for the 2018 Ram 1500 goes beyond simply draining the old fluid; it is a systematic process that ensures the new oil performs to its highest potential. The procedure involves lifting the truck safely, removing the drain plug while being mindful of the hot oil temperature, and replacing the factory filter with a new one primed with fresh oil. Mechanics recommend tightening the new filter by hand to the manufacturer’s specification—usually just snug plus a quarter turn—to avoid damaging the rubber gasket or stripping the mounting surface.
Torque Specifications Matter
Over-tightening the oil drain plug is a common mistake that leads to stripped threads and expensive repairs down the line. For the 2018 Ram 1500, the drain plug requires a specific torque, typically around 20 foot-pounds, to create a proper seal without deforming the aluminum pan. Similarly, the oil filter cap needs to be secured to the correct specification to prevent leaks. Using a torque wrench for both the drain plug and the filter ensures the integrity of the oil pan and the reliability of the seal for thousands of miles.
