Best Oil for Jeep 4.0 Engine

The Jeep 4.6 engine is one of the most renowned AMC engines. While it’s a powerful engine, it requires a regular engine oil change. The following is a guide for the best oil engine for your jeep 4.0 engine.

The first Jeep 4.0 engine is a 242 cu engine released in 1986 by American Motor Company for the 1987 Jeep models and was kept by Chrysler after the takeover in the same year. It is commonly found in Jeep’s Cherokee, Comanche, Wagoneer, Wrangler, and Grand Cherokee models. It is the last of AMC’s straight-six engines and is regarded as one of Chrysler’s 4×4 best off-road engines and can run for up to 200, 000 miles without any overhaul making the Jeep a sturdy car that can last a lifetime. One of the most important you can make is finding your Jeep 4.0 engine the right compatible oil which we’ll cover in this article. The following are the best oils for your Jeep 4.0 engine.

List of The Best Oil for Jeep 4.0 Engine

Valvoline High Mileage Synthetic Blend Motor Oil

The Valvoline High Mileage Motor Oil is an upgrade if you’ve been using conventional oils as it’s a synthetic blend with exceptional molecular structure uniformity. It has a viscosity rating of 10W-30 and contains antioxidants that prevent the breakdown of oil which dissolves sludge and deposits. Its premium formula includes additional detergents which keep your engine free from metallic deterioration because of its superb wear protection. Its heavy-duty bottle structure can withstand any external pressure and comes with a pour spout that helps prevent spillage on its easy to pull tab. This is the only synthetic blend oil to make it to the list and your 4.0 Jeep can go for over 200, 000 miles.

Pros

• Protects against thin film wearing
• Enhances performance
• Contains inbuilt seal conditioning agents
• Durable
• Prevents oil breakdown

Cons

• Unsuitable for severely worn-out engines

Mobil 1 (120770) High Mileage 10W-30 Motor Oil

This is a common brand with the Mobil 1 High Mileage being one of their best when it comes to your Jeep 4.0 engine especially the old one as it’s a fully synthetic high mileage oil. This oil uses Moil 1’s proprietary formula to stop or slow any oil leaks and can handle any demands of your Jeep’s 4.0 engine. Mobil 1 is a leading player in the high -end motor technology making it a powerhouse in the engine oil industry. This product of theirs is recommended for cars with over 75, 000 miles on them. Its efficiency and performance with the Jeep wrangler jk hit the roof making it the best oil for the model. The oil has a stable formula that’s fully synthetic and has few impurities to prevent pollution of your engine. It has a viscosity rating of 10W-30 that cushions it against heat or winter of about 10°C maintaining its active status.

Pros

• Oil leak stop/slow formulation
• High-mileage formulation of over 75, 000
• Reduces deposits and sludge
• Uniform molecular concentration

Cons

• Leakages when switching back to regular oil
• The addictive swell initially

Pennzoil Platinum 5W-30 Full Synthetic

This Pennzoil Platinum oil has superb features to support your engine when in action. It has a viscosity rating of 5W-30 to maintain its fluidity in enduring temperature conditions and prevents unwanted loss of engine power. It contains fewer impurities to help deliver mechanical stability. Its protective formula of combined additives ensures the pistons remain clean and protected against friction and wear. This engine oil gives your Jeep 4.0 engine a better fuel economy of about an extra 550 miles yearly.

Pros

• Cleanliness
• Protection against wear
• Stable formulation
• Increases fuel mileage

Cons

• Lessened additive package

Royal Purple SAE Synthetic Motor Oil

Royal Purple is among Jeep user’s favorite though it’s one of the most expensive oils. This oil also doubles up as an engine lubricant and is compatible with a gas containing ethanol. It protects against corrosion in humid climatic conditions using its anti-wear additive and increases fuel efficiency. Its 5W-30 viscosity rating ensures it can withstand both high-temperature stress and low-temperature extremity and minimizes metal-to-metal contact thus reducing friction and optimizing fuel efficiency. The pistons are kept clean throughout by its anti-wear agents and sludge build-up merely occurs.

Pros

• Leakage prevention
• Fewer sludge deposits
• Horsepower optimization
• Protection against corrosion
• COmpatibility with ethanol fuels

Cons

• Costly

Castrol 03129C EDGE High Mileage 10W-30 Advanced Full Synthetic Motor Oil

Castrol is one of the world’s most trusted brands and has a reputation for developing high-quality product formulation. The Castrol 03129C EDGE High Mileage 10W-30 Advanced Full Synthetic Motor Oil makes use of the patented Fluid Titanium Technology to work well under pressure by allowing oil to stick to the friction surfaces better to ensure your Jeep 4.0 engine is protected from friction and wear. It retains cleanliness using a protective thin layer and its additives minimize oxidation guaranteeing engine durability.  It delivers good fuel economy especially if your vehicle is a high-mileage Jeep with 100, 000 miles. Although the recommended viscosity is 5W-30 in cold conditions, the 10W-30 should be sufficient on your Jeep.

Pros

• Pure synthetic oil composition
• Lasts for many miles
• Compatible with standard engines
• Excellent internal cleanliness
• Works in all temperature conditions

Cons

• Replacement may be needed sooner
• The seal has problems

Pennzoil Ultra Platinum 10W-30

Pennzoil, an American company, was the first to produce more oils from natural gas. This product from Pennzoil is derived from natural gas and can provide your Jeep with the highest fuel economy since it works in both extreme temperatures making it one of the best selling full synthetic engine oils. Pennzoil crafted this oil to take care of sludge that builds-up and its conventional oil formula is meant for older versions like the Jeep 4.0 engines. The formula meets API SP and other industry standards and includes seal conditioning agents suited for both modern and older vehicles. Your engine can go for 75, 000 miles without an engine change.

Pros

• Improved fuel economy
• Compatible with a wide range of engines
• Protects against wear
• Prevents engine loss of power

Cons

• The bottle is prone to leakage

Valvoline Advanced Motor Oil

In the 5W-30 space, no engine oil beats the Valvoline Full Synthetic Advanced Motor Oil as it’s designed for engines such as your hard-working Jeep 4.0 engine. Valvoline is manufactured in the US and is known for its high standards in the industry. It has a complete synthetic based-components formulation with fewer impurities with absolute uniformity in its concentration to guarantee efficiency and thus saving you costs with increased fuel efficiency. It protects your engine from heat stress and metal wear as the liquid remains functional in a wide temperature range and works great in sub-zero conditions like the Midwest’s. Valvoline Advanced Motor Oil is compatible with both synthetic and conventional oils.

Pros

• Protects a wide range of temperatures
• Increased fuel economy
• Stable formula
• Provides wear protection

Cons

• Low-mileage
• Bottle may leak

Buyer’s Guide for the Best Jeep 4.0 Engine

Buying the best oil for your Jeep 4.0 depends on the following factors.

Oil capacity

The standard oil capacity for a 4.0 Jeep is six quarts. Most oils on the other hand come in single and five-quart volume bottles, so to fill up your engine fully, you’ll need each.

Type of oil

Jeep doesn’t give any specific recommendations when it comes to the oil type. The Jeep 4.0 engine is good with both the conventional and synthetic oils since it’s an old engine model. Conventional oils are made of crude oil and are least superior while synthetic blends have a conventional oil base but with superior quality to conventional oils. Fully synthetic oils are the most expensive but compensate this with premium quality since they don’t have any crude oil. Since it’s all about preferences, you can choose from a conventional fully synthetic or synthetic blend of oil.

Oil viscosity

Different motor oils have different viscosity ratings such as 0W-30, 10W-40, 20W-50, 5W-30 among others. Not every viscosity rating can properly work on your Jeep engine. The 10W-30 and 5W-30 are the recommended viscosity ratings for the Jeep 4.0 engine and a slightly thick 10W-40 can also be used. The 5W-30 offers the best service in cold conditions. However, the 10W-30 is the best and by far the most compatible.

Car engine

Several Jeep models have made use of the 4.0 engine with Cherokee and Wrangler being the most notable ones. However, it is advised you check your car’s manual for compatibility and the recommended oil type to save you any unwanted hassles.

Additives

Additives are an important ingredient in modern motor oils and they contain a chemical to perform a specific task. Additives can clean your internal engine parts by dissolving existing deposits which helps prevent build-up.

Packaging

The quality of the bottle holding the oil is a concern to many customers. The seal, grips, and spouts to make handling and pouring easy. When you buy the motor oil, don’t forget to check for any leakages from holes.

How to Change the Oil on your Jeep 4.0 Engine

To change the oil, raise your Jeep using a jack stand or ramps. TIs best to do this when the engine is a bit warm to enable the oil to drain out quickly and safely. Place a drain pan below the drain plug underneath the main oil pan. Carefully, unplug the drain using a wrench and let the oil drain to its last drop into the pan. Put back the drain plug and close it tight. Ensure there are no leaks or gaps. Go to the passenger’s side and place your drain pan under the oil filter. Remove the oil filter and replace it with a new filter before filling the new engine oil. Unwrench the gasket O-ring and remove the old filter ensuring the rubber gasket is not attached to the engine block. Push the new filter to fit and tighten it using your hand or a wrench. Open the cap and fill the engine with 5-6 quarts of fresh engine oil then put the cap back and tighten it until it clicks. Start the car and let it run for a few minutes. Then check underneath for any oil leaks and use a dipstick to check the oil level. Lower the vehicle.

FAQs

What is the required oil capacity for my Jeep 4.0 engine?

The standard 4.0 engine takes 6 quarts or 5.7 liters of oil.

What is the best oil for my Jeep 4.0 engine?

Motor oils with a viscosity rating of 10W-30 are recommended. However, 5W-30 can also work.

Conclusion

The Castrol 03129C EDGE High Mileage 10W-30 Advanced Full Synthetic Motor Oil is our top pick. It’s a premium grade oil from a trusted brand and can protect your Jeep 4.0 engine from wear as well as giving it a smooth start in low temperatures regardless of how old your Jeep is. It isn’t costly giving you value for money.