The 2018 Jeep Grand Cherokee equipped with the robust 6.4L V8 HEMI engine demands lubricants that can handle high thermal loads and rigorous driving conditions. Whether you are navigating steep mountain passes, towing heavy loads, or simply enjoying daily commutes, the performance of this vehicle relies heavily on the quality of the fluids circulating through its systems. Using factory-fill or conventional oils often falls short of the protective standards required by modern high-output engines, leading to premature wear, sludge buildup, and reduced fuel efficiency. By switching to premium synthetic formulations, you ensure that critical components like the cylinder walls, pistons, and valve trains receive the necessary protection against friction and corrosion. This guide outlines the specific fluid capacities, product recommendations, and maintenance schedules to keep your Grand Cherokee operating at peak performance.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-40 100% Synthetic Motor Oil – Offers unmatched engine protection with the capability to extend service intervals up to 25,000 miles or one year, specifically designed to handle the high-output demands of the 6.4L V8.
- AMSOIL OE 0W-40 100% Synthetic Motor Oil – A cost-effective yet high-performance alternative that fights sludge and deposits effectively while meeting strict manufacturer specifications for modern engines.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – Features a precise blend of synthetic base oils and premium additives tailored for the unique demands of European-style engines, providing excellent performance across all temperatures.
- AMSOIL Oil Filter – Delivers 99 percent filtering efficiency at 20 microns, allowing for lower restriction and keeping engine parts fully lubricated while capturing small, wear-causing contaminants better than competing filters.
- WIX Oil Filter – Offers premium media improvements over original equipment manufacturer-branded filters, ensuring reliable filtration and protection during extended oil change intervals.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed to withstand the rigors of heavy towing and elevated temperatures while remaining fluid in sub-zero conditions for smooth, shudder-free shifts.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Provides excellent protection against wear and sludge with outstanding cold-weather performance to ensure reliable operation in all climates.
- AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube – Advanced protection for front and rear differentials, controlling thermal runaway and providing friction modifiers ideal for limited-slip applications.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid formulation that protects all cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range for superior stopping power.
Engine Oil and Filtration Requirements
The heart of your 2018 Jeep Grand Cherokee is the 6.4L V8 engine, which generates significant power and heat. To maintain its performance and longevity, the manufacturer explicitly requires the use of synthetic oil. The capacity for this engine, including a filter change, is 7.0 quarts. It is crucial to note that after a refill, you must check the oil level to ensure it is within the proper operating range. The oil drain plug should be torqued to 20 ft/lbs to prevent leaks or thread damage. For those seeking the ultimate in protection, AMSOIL Signature Series 0W-40 Motor Oil is formulated to withstand horsepower loss and wear, offering superior thermal stability compared to conventional oils. This fluid is particularly beneficial for drivers who tow heavy loads or operate in extreme temperatures, as it resists breakdown and oxidation effectively. If you prefer an OE-branded approach that still utilizes 100% synthetic technology, the AMSOIL OE 0W-40 Motor Oil is an excellent choice, offering a balance of performance and value while effectively fighting sludge and deposits.
Filtration is equally critical when using high-performance synthetic oils. Even with a clean engine, microscopic contaminants can accumulate and cause wear over time. The AMSOIL Oil Filter is engineered to provide filtering efficiency of 99 percent at 20 microns, which helps reduce engine wear by capturing small particles that standard filters might miss. It also offers greater capacity for contaminants, which is essential for extended service intervals. For those who prefer a brand-name aftermarket option, the WIX Oil Filter is a robust alternative that offers improvements over OEM-branded filters. Additionally, keeping the engine breathing clean air is vital for the 6.4L HEMI. The WIX Air Filter utilizes premium media to improve airflow and filtration, ensuring that the engine receives the cleanest air possible to maximize combustion efficiency and power output.
Transmission and Drivetrain Maintenance
The automatic transmission in the 2018 Grand Cherokee, specifically the 8HP70 model, is a sophisticated component that relies on precise fluid properties for smooth shifting and longevity. The total fill capacity for the 8-speed transmission is 8.8 quarts. Using a synthetic transmission fluid is highly recommended to handle the heat generated during heavy towing or spirited driving on challenging terrain. AMSOIL Signature Series Fuel-Efficient Automatic Transmission Fluid is designed to remain fluid in sub-zero temperatures and provide reserve protection during heavy use, reducing the risk of slippage and shudder. For a more economical option that still delivers synthetic performance, the AMSOIL OE Fuel-Efficient Transmission Fluid offers excellent cold-weather performance and resistance to sludge, promoting smooth, shudder-free shifts.
The transfer case and differentials are also subject to heavy loads, especially given the vehicle’s four-wheel-drive capabilities. For the MP3010 transfer case, which uses Mopar ATF+4 specifications, the AMSOIL Signature Series Multi-Vehicle Automatic Transmission Fluid is a suitable replacement that meets the required standards. It withstands the rigors of high torque and elevated temperatures while remaining stable in cold weather. For the front and rear differentials, which require 75W-85 synthetic oil, AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube is the ideal choice. This heavy-duty gear lube controls thermal runaway, protects against rust and corrosion, and contains friction modifiers specifically for limited-slip applications. Whether you have the 195FIA front differential (1.9 pints capacity) or the 195RIA rear differential (1.9 pints capacity), or the 230RIA rear differential with ELSD (2.7 pints capacity), this synthetic lubricant ensures extended oil and seal life while helping to reduce operating temperatures.
Cooling and Brake System Fluids
Maintaining the cooling system is essential for preventing overheating, which can be a concern for high-displacement engines under load. The cooling system capacity for the 2018 Jeep Grand Cherokee is 16.1 quarts. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a pre-mixed 50/50 ethylene glycol formulation that is phosphate, nitrite, silicate, and borate-free, making it compatible with all other antifreeze colors and safe for all cooling system metals, gaskets, and hoses. It offers protection up to 150,000 miles or 5 years, whichever comes first. For those who prefer concentrated coolants, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a viable option, offering even longer service intervals and protection against metallic corrosion and erosion.
The braking system relies on DOT 3 hydraulic brake fluid, and maintaining its integrity is crucial for safety. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid provides a stable viscosity over a wide temperature range, ensuring excellent responsiveness in both the ABS and traction-control systems. This fluid resists boiling and moisture absorption better than conventional fluids, helping to maintain a firm pedal feel and reducing the risk of brake fade during intense driving conditions.
About the Vehicle
The 2018 Jeep Grand Cherokee represents a peak in the continued evolution of the WK2 generation, blending rugged off-road capability with upscale comfort and modern technology. Powered by the 6.4L HEMI V8 in the specific configuration discussed here, this vehicle offers substantial horsepower and torque, making it a formidable choice for both daily driving and serious towing. The platform is built on a body-on-frame chassis architecture that has been refined over the years to provide a smooth ride on pavement while retaining the durability needed for trails. Owners of this vehicle often appreciate its versatile nature, as it can seamlessly transition from a family hauler to a weekend adventurer.
The 6.4L engine, part of the modern HEMI family, is renowned for its smooth power delivery and reliability. However, like any high-performance internal combustion engine, it operates under significant stress, particularly in the upper cylinder region where the direct injection system creates intense heat and pressure. This specific setup is susceptible to pre-ignition and carbon buildup on the intake valves and pistons, common issues in GDI (Gasoline Direct Injection) engines. Regular maintenance with high-quality synthetic oils that resist oxidation and contain robust detergent packages can help mitigate these problems. The vehicle also features advanced four-wheel-drive systems, such as the Quadra-Drive II, which rely heavily on the proper friction characteristics of the differential and transfer case fluids to function correctly.
Several known issues often plague this engine and platform, which premium lubricants can help manage. One common challenge is the accumulation of carbon deposits on intake valves, which can lead to reduced performance and rough idling. Using a fuel additive like AMSOIL P.i.® Performance Improver periodically can help clean GDI injectors and restore flow rates. Another issue is the potential for seal shrinkage in older vehicles, leading to oil leaks; synthetic fluids with seal conditioners can help maintain gasket flexibility. Additionally, the high thermal load can accelerate the breakdown of standard transmission and gear fluids, resulting in shudder or poor shift quality; synthetic alternatives are designed to resist this thermal degradation. Finally, brake fluid absorption of moisture over time can lead to a spongy pedal and reduced braking efficiency; switching to a high-boiling-point synthetic brake fluid can prevent this and ensure consistent stopping power. By addressing these potential pain points with the correct AMSOIL products, owners can extend the service life of their Grand Cherokee and enjoy a more reliable driving experience.