Every Jeep owner knows the thrill of adventure, whether it’s conquering a rocky trail or simply enjoying the open road. But beneath that rugged exterior, your 2018 Grand Cherokee relies on a healthy heart: its engine. And at the core of engine health is the right oil.
You probably agree that keeping your Jeep running strong is a top priority. Skimping on maintenance, especially when it comes to engine oil, can lead to costly repairs and cut your adventures short. That’s where we come in.
This comprehensive guide will equip you with everything you need to know about 2018 Jeep Grand Cherokee oil, from choosing the correct type to performing your own oil change. We promise to demystify engine oil, help you select the best options for your specific engine (Pentastar V6, HEMI V8, or EcoDiesel V6), and walk you through the DIY process safely and confidently.
By the end of this article, you’ll understand exactly what your Jeep needs to perform its best, whether you’re tackling daily commutes or navigating challenging off-road terrain. Let’s dive in and keep your Grand Cherokee roaring!
Understanding Your 2018 Jeep Grand Cherokee Oil Needs
Your Jeep’s engine is a complex piece of machinery, and engine oil is its lifeblood. It lubricates moving parts, dissipates heat, cleans components, and helps seal combustion chambers. Using the correct oil is non-negotiable for longevity and performance.
The Right Viscosity: Why It Matters
Oil viscosity refers to its thickness or resistance to flow. It’s indicated by the “W” (winter) rating and the second number on the oil bottle (e.g., 5W-20, 5W-30). The first number tells you how well the oil flows when cold, while the second number indicates its flow at operating temperature.
Using the wrong viscosity can lead to excessive engine wear, poor fuel economy, and even engine damage. Thicker oil might not flow quickly enough at startup, while thinner oil might not provide adequate protection under high loads or temperatures.
Conventional vs. Synthetic: What’s Best for Your Jeep?
This is a common question among DIYers. Conventional oil is refined from crude oil, offering basic lubrication.
Synthetic oil is engineered in a lab, providing superior performance, better resistance to temperature extremes, and extended drain intervals. Many modern engines, especially those in the 2018 Grand Cherokee, are designed for and often require synthetic or synthetic blend oils.
For off-road enthusiasts or those who tow regularly, synthetic oil offers an extra layer of protection against breakdown under severe conditions. It’s an investment that pays off in engine longevity.
Decoding API and ILSAC Standards
When you look at an oil bottle, you’ll see ratings from organizations like the American Petroleum Institute (API) and the International Lubricant Standardization and Approval Committee (ILSAC). These symbols ensure the oil meets specific performance and quality standards.
Look for the “API Donut” symbol, which indicates the service category (e.g., SN, SP for gasoline engines). The “Starburst” symbol from ILSAC certifies energy-conserving oils. Always match these ratings to what your Jeep’s owner’s manual specifies. This guarantees compatibility and proper engine protection.
Choosing the Best 2018 Jeep Grand Cherokee Oil for Your Engine
The 2018 Grand Cherokee came with several powerful engine options, and each has specific oil requirements. Knowing your engine is the first step to making the right choice.
Pentastar 3.6L V6 Recommendations
The ubiquitous 3.6L Pentastar V6 is a workhorse, known for its reliability and decent power. For this engine, Jeep generally recommends 5W-20 full synthetic or synthetic blend oil.
Brands like Pennzoil Ultra Platinum, Valvoline Advanced Full Synthetic, or Mobil 1 are excellent choices. Ensure the oil meets Chrysler’s MS-6395 specification, which will be listed on the bottle. This spec is crucial for proper lubrication and warranty compliance.
HEMI 5.7L V8 Recommendations
The HEMI V8 delivers robust power, perfect for towing or spirited driving. These engines often have Cylinder Deactivation Technology (MDS), which requires specific oil properties.
The recommended oil for the 5.7L HEMI is typically 5W-20 full synthetic oil that meets Chrysler’s MS-6395 specification. Some owners prefer a 5W-30 in very hot climates or for heavy towing, but always consult your owner’s manual first. The right oil helps MDS function correctly and prevents lifter issues.
EcoDiesel 3.0L V6 Specifics
The EcoDiesel is a different beast entirely, with very specific oil needs due to its diesel particulate filter (DPF) and other emissions equipment. You absolutely cannot use standard gasoline engine oil in an EcoDiesel.
For the 3.0L EcoDiesel, you need a low-ash, C-rated diesel engine oil, typically 5W-30 or 5W-40, that meets Chrysler’s MS-11106 specification. Brands like Shell Rotella T6 or Mobil 1 ESP are popular choices. Using the wrong oil can clog your DPF and lead to extremely expensive repairs.
Off-Road and Towing Considerations
If your 2018 Grand Cherokee sees heavy off-road action, frequent towing, or operates in extreme temperatures, consider upgrading to a premium full synthetic oil. These oils offer enhanced thermal stability and shear resistance.
Such conditions put extra stress on your engine and its lubricants. A high-quality synthetic provides superior protection, reducing wear and maintaining performance when your Jeep is working hardest. You might also consider slightly shorter oil change intervals under these severe conditions.
The DIY 2018 Jeep Grand Cherokee Oil Change: Step-by-Step
Performing your own oil change is a rewarding DIY task that saves money and helps you connect with your vehicle. Let’s get your 2018 Jeep Grand Cherokee oil changed safely and efficiently.
Tools and Materials You’ll Need
Gathering your supplies beforehand makes the job much smoother:
- New engine oil (correct type and quantity for your engine)
- New oil filter (e.g., Mopar, Wix, K&N)
- Oil filter wrench (cap style is often best for canister filters)
- Drain pan (large enough for your oil capacity)
- Socket wrench and appropriate socket for the drain plug (often 13mm or 16mm)
- Funnel
- Rags or shop towels
- Gloves (nitrile or latex)
- Jack and jack stands (if needed for clearance)
- Wheel chocks
- Safety glasses
Safety First: Pre-Service Checklist
Your safety is paramount. Always follow these steps:
- Park your Jeep on a level surface.
- Engage the parking brake.
- Place wheel chocks behind the rear wheels.
- If you need more clearance, use a jack to lift the front and secure it with jack stands. Never work under a vehicle supported only by a jack.
- Ensure the engine is warm but not scalding hot. A warm engine helps the oil drain better.
Draining the Old Oil
Locate the oil pan and drain plug underneath your Jeep. The oil pan is a large metal reservoir at the bottom of the engine.
- Position your drain pan directly under the drain plug.
- Using your socket wrench, carefully loosen the drain plug. Be ready for the oil to come out once the plug is free.
- Remove the plug and allow all the old oil to drain into the pan. This can take 10-15 minutes.
- Inspect the drain plug and its washer. If the washer is crushed or damaged, replace it. Many new oil filters come with a fresh drain plug washer.
- Once the oil stream slows to a drip, clean the area around the drain plug and reinstall it, tightening it snugly. Do not overtighten, as this can strip the threads.
Replacing the Oil Filter
The oil filter location varies by engine. On Pentastar V6 and EcoDiesel engines, it’s typically a cartridge filter accessible from the top of the engine bay. HEMI V8s usually have a spin-on filter on the side of the engine block.
- For cartridge filters: Use your oil filter wrench to loosen the cap. Be prepared for a small amount of oil to spill. Remove the old cartridge and O-rings. Lubricate new O-rings with fresh oil and install them, then insert the new filter and tighten the cap to spec.
- For spin-on filters: Position your drain pan underneath. Use your oil filter wrench to loosen and remove the old filter. Be careful, as it will be full of oil.
- Before installing the new spin-on filter, apply a thin film of fresh oil to its rubber gasket. This helps create a good seal.
- Hand-tighten the new filter until it’s snug, then give it an additional quarter to half turn with the wrench, following the instructions on the filter.
Adding Fresh Engine Oil
This is where your fresh 2018 Jeep Grand Cherokee oil goes in.
- Locate the oil filler cap on top of your engine. It’s usually marked with an oil can symbol.
- Place a funnel into the filler neck.
- Slowly pour the recommended amount of new engine oil into the engine. Refer to your owner’s manual for the exact capacity.
- Once all the oil is added, replace the oil filler cap securely.
Final Checks and Resetting the Oil Life Monitor
Almost done! Don’t skip these crucial steps:
- Start the engine and let it run for a minute or two. Check underneath the Jeep for any leaks around the drain plug or oil filter.
- Shut off the engine and wait a few minutes for the oil to settle back into the pan.
- Pull the dipstick, wipe it clean, reinsert it fully, then pull it out again to check the oil level. It should be between the “MIN” and “MAX” marks. Add a small amount of oil if needed.
- Reset your Jeep’s oil life monitor. The exact procedure varies slightly, but typically involves turning the ignition to “ON” (without starting the engine), pressing the accelerator pedal to the floor three times within 10 seconds, then turning the ignition off. Consult your owner’s manual for the precise steps for your trim level.
- Properly dispose of your old oil at a local auto parts store or recycling center. Never pour it down the drain or into the ground.
Common Oil-Related Issues and Troubleshooting
Even with proper maintenance, issues can arise. Knowing how to diagnose them quickly can save you from bigger problems.
Oil Pressure Warning Light
If your oil pressure warning light comes on, it’s a serious sign. Pull over safely as soon as possible and shut off the engine. Driving with low oil pressure can cause catastrophic engine damage.
First, check your oil level on the dipstick. If it’s low, add oil. If the level is fine, it could indicate a faulty oil pressure sensor or a more severe internal engine problem. Get it checked by a professional immediately.
Excessive Oil Consumption
Some engines, particularly HEMI V8s, are known to consume a small amount of oil between changes. However, excessive consumption (e.g., needing to add a quart every 1,000 miles) is a concern.
This can be due to worn piston rings, valve seals, or PCV system issues. Keep a close eye on your oil level and consult a mechanic if consumption seems unusually high for your 2018 Jeep Grand Cherokee.
Oil Leaks: Identifying and Addressing Them
Puddles under your Jeep are never a good sign. Common oil leak culprits include:
- Loose drain plug or faulty washer
- Incorrectly installed or damaged oil filter gasket
- Valve cover gaskets
- Oil pan gasket
- Front or rear main seals
- Oil pressure sensor
Clean the area thoroughly, then run the engine and observe where the leak originates. Small leaks can sometimes be addressed with a simple fix, but larger or persistent leaks may require professional attention.
Extending Your Engine’s Life: Beyond the Oil Change
An oil change is a fundamental part of maintenance, but a few other habits can significantly extend your engine’s life.
Regular Oil Level Checks
Don’t wait for the next oil change interval to check your oil. Make it a habit to check the oil level every few weeks, or before a long road trip or off-road excursion. This is especially true for vehicles that tow or are driven hard.
Catching a low oil level early can prevent serious engine damage. It only takes a minute and provides invaluable peace of mind.
Understanding Your Driving Habits
Your driving style directly impacts how often your oil needs changing. Frequent short trips, stop-and-go city driving, heavy towing, or aggressive off-roading are all considered “severe service” conditions.
Under these conditions, your oil breaks down faster. Consider shortening your oil change intervals from the manufacturer’s maximum recommendation to protect your engine. For example, if your manual suggests 10,000 miles, you might opt for 5,000-7,500 miles under severe conditions.
The Importance of Quality Filters
The oil filter is just as important as the oil itself. A cheap, low-quality filter might not capture contaminants effectively or could restrict oil flow, leading to premature engine wear.
Always use a reputable brand of oil filter that meets or exceeds OEM specifications. This ensures maximum filtration efficiency and proper oil flow to keep your engine clean and well-lubricated.
Frequently Asked Questions About 2018 Jeep Grand Cherokee Oil
Let’s tackle some common questions to round out our discussion on 2018 Jeep Grand Cherokee oil.
How often should I change the oil in my 2018 Grand Cherokee?
Generally, for the gasoline engines (3.6L V6 and 5.7L V8), the manufacturer recommends every 10,000 miles or 12 months, whichever comes first, when using synthetic oil. For the EcoDiesel, it’s typically 10,000 miles or 12 months. However, if you drive under “severe service” conditions (heavy towing, off-roading, extreme temperatures, dusty environments, frequent short trips), it’s wise to shorten that interval to 5,000-7,500 miles.
Can I mix different types of engine oil?
While not ideal, mixing conventional and synthetic oil (creating a “synthetic blend”) is generally not harmful in an emergency if you’re just topping off. However, for a full oil change, always stick to the type specified for your engine. Mixing different viscosities or specifications should be avoided unless explicitly stated by the manufacturer.
What happens if I use the wrong oil viscosity?
Using the wrong viscosity can lead to several problems. Oil that’s too thick might not circulate properly at startup, causing dry starts and increased wear. Oil that’s too thin might not provide adequate lubrication under high operating temperatures, leading to premature wear and potential engine damage. Always follow the manufacturer’s recommended viscosity (e.g., 5W-20 for Pentastar/HEMI).
Is it normal for my HEMI to consume some oil?
Yes, it can be. Many modern engines, including the 5.7L HEMI V8, are designed to consume a small amount of oil as part of their normal operation, especially if they have cylinder deactivation technology. However, excessive consumption (more than a quart every 1,000-2,000 miles) is not normal and should be investigated by a mechanic.
What’s the best oil for a 2018 Grand Cherokee that sees heavy off-road use?
For heavy off-road use, always opt for a high-quality, full synthetic oil that meets your engine’s specific requirements (e.g., 5W-20 MS-6395 for Pentastar/HEMI, 5W-30/40 MS-11106 for EcoDiesel). Full synthetics offer superior protection against thermal breakdown, shear, and sludge formation, which are all more likely under the extreme stress of off-roading. Consider shortening your oil change intervals as well.
Taking care of your 2018 Jeep Grand Cherokee oil is one of the most important things you can do for its longevity and performance. Whether you’re a seasoned DIYer or just starting, understanding your Jeep’s needs and following proper maintenance steps will keep it running strong for countless adventures.
Don’t let neglected maintenance cut your trail time short. Get familiar with your Jeep, choose the right products, and tackle that oil change with confidence. Your Grand Cherokee will thank you for it, delivering reliable performance whether you’re on the pavement or far off the beaten path. Stay safe and happy wrenching!
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