Selecting the correct 2018 Ram 1500 oil type is fundamental to preserving the longevity and peak performance of one of America’s best-selling trucks. While the 5.7-liter HEMI V8 and the 3.6-liter Pentastar V6 engines are robust, they demand specific lubricants to operate efficiently under various stress conditions. Using the wrong viscosity or incorrect certification can lead to decreased fuel economy, increased wear, and potentially costly repairs down the line.
Understanding SAE Viscosity Ratings
Before diving into specific brands, it is essential to understand the numbers on the oil bottle. The Society of Automotive Engineers (SAE) viscosity rating dictates how the oil flows at different temperatures. For the 2018 Ram 1500, the most common and recommended viscosity is 5W-20. The "5W" signifies the oil's flow during cold starts—lower numbers flow better in freezing temperatures—while the "20" indicates the thickness of the oil at high operating temperatures. This multi-grade formulation provides the best balance of protection during cold mornings and stability during hot summer drives or when towing heavy loads.
API Service Standards and Certification
Beyond viscosity, the oil must meet specific performance standards set by the American Petroleum Institute (API). For the majority of 2018 Ram 1500 models, the minimum requirement is API SN. However, if your truck is equipped with the available EcoDiesel V6 engine, the manufacturer strongly recommends API CK-4 or FA-4 certification. These higher standards ensure the oil can handle the increased pressures and sulfated particulates associated with diesel combustion. Using an SN oil in an EcoDiesel engine can eventually lead to increased soot buildup and reduced turbocharger life.
Synthetic vs. Conventional Oil
When deciding on the 2018 ram 1500 oil type, drivers must choose between conventional, synthetic blend, or full synthetic. Full synthetic oil is generally the superior choice for the Ram 1500 due to its superior temperature stability and longevity. It flows better in cold weather, maintains viscosity under high heat, and contains fewer impurities. While the price per quart is higher, the extended change intervals—often up to 7,500 to 10,000 miles for synthetics—can offset the initial cost over the life of the vehicle.
OEM-Approved Specifications
Chrysler, the manufacturer of the Ram 1500, sets specific standards for the lubricants used in their vehicles. For many 2018 models, especially those with the HEMI engine, the oil must meet Chrysler MS-11106 (PTS) or similar original equipment manufacturer (OEM) approval. Checking the oil cap or the owner’s manual for this sticker is critical. Aftermarket brands that meet these OEM specifications guarantee that the detergent packages and additives are compatible with the delicate variable valve timing (VVT) systems found in modern Ram engines.
Best Oil Options for Towing and Hauling
If the 2018 Ram 1500 is used as a workhorse, the oil type must change to accommodate the extra thermal stress generated by towing. When pulling a trailer, the engine operates at higher RPMs for extended periods, causing oil temperatures to spike. In these scenarios, many mechanics recommend upgrading to a 5W-30 or even a 10W-30 synthetic blend. These higher viscosities create a thicker oil film, providing a stronger barrier between moving parts and reducing the risk of oil thinning under extreme load.
