What Is The Best Oil For Jeep 4.0 Engine?

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Jeep has been known for its exceptional quality over the years. And you are finding the best oil for your Jeep 4.0 engine to remain efficient for a lifetime?

Well, the engine is the heart of a vehicle, while the oil is the blood. So, you have to pay attention to some essential features before making a decision.


However, you don’t have to be confused. This article will help you to make your choice easier.

Let’s dive in!

Jeep 4.0 Engine Overview

The Jeep 4.0 engine is iconic throughout the automobile industry. It is strong, reliable, and efficient. All Jeep fans will always accept the fact that this machine is legendary. 

Its long crankshaft made it perfect for passing over off-road barriers. The oil capacity of the Jeep 4.0 engine is six quarts.

In those days, millions of 4.0L engines were in the automotive market. Spare parts were not difficult to find at all. The jeep kept the engine for more than two decades. The car models that use the 4.0L engine include:

  • Jeep Wrangler (from 1991 to 2006)
  • Jeep Grand Cherokee (from 1993 to 2004)
  • Jeep Cherokee (from 1987 to 2001)
  • Jeep Wagoneer (from 1987 to 1990)
  • Jeep Comanche (from 1987 to 1992)

The Jeep Cherokee used the engine from 1987 to 2001. The Wrangler also used it from 1991 to 2006. The 4.0 engine was capable of producing 190-hp at 4,600rpm. It also had 12 overhead valves. Unfortunately for Jeep lovers, Chrysler retired the engine in 2006. The 2007 Wrangler had a 3.8-litre OHV V6 engine.


The next section will examine two factors that affect your decision – viscosity and season of the year.

Valvoline 10W-30
Valvoline 10W-30

Best For High Mileage Engine

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Mobil 1 Full Synthetic 5W-30
Mobil1 5W-30

Best For Fall and Winter

Mobil 1 Synthetic 10W-30
Mobil1 10W-30

Best For Spring and Summer

Feature #1: Oil Viscosity and Weather

Before you purchase oil for your jeep 4.0 engine, you need to note the oil’s viscosity. Therefore, you need to understand the marking associated with oil viscosity ratings. Let us start by defining viscosity.

The concept of viscosity is similar to that of friction. Viscosity defines the ease with which a fluid moves at a particular temperature. When a car engine operates, thermodynamic processes and heat transfer cause the oil to heat up.

Imagine oil that is very hot and tries to move through a cylindrical passage. The period it takes for the fluid to pass through that path defines its viscosity. The thickness of the oil determines the rate at which the oil will flow. Thin-oil will flow faster compared to a thick oil.

Oil viscosity rating comes in forms like 0W-30, 0W-40, 5W-30, and so on. The letters and figures have meaning. You need to understand what they mean before purchasing any oil.

The number before the W stands for the viscosity of the oil at 0 degrees Fahrenheit. The letter “W” stands for winter. W refers to the oil’s viscosity during cold weather.

Less viscous oil is better during the winter because it flows faster at a low temperature. Most parts of the engine need constant lubrication so that the car will kick start.

The number after the W also relates to viscosity as well. However, it defines the viscosity of the oil at a temperature of 100 degrees Celsius. A low number indicates a low viscosity and vice versa. The best type of oil for a warm season is the thick type.

Best Oil for Spring and Summer – 10W30

10W30 remains one of the best oil grades for the warm seasons. Compared to 0W30 and 5W30, 10W30 is thicker, and it doesn’t break down easily under high temperatures.

This resilient viscosity factor makes it perfect for high-performance machines like the Jeep 4.0 engine. 10W30 is perfect for cars that can carry heavy loads, such as the Jeep Cherokee.

Mobil 1 120762 Synthetic Motor Oil 10W-30

Mobil 1 Synthetic 10W-30
Mobil 1 Synthetic 10W-30
With its excellent lubrication and wear protection performance, Mobile 1 10W30 is the best bet for every driving style.

This 160 fluid ounces product is the best for an off-road gasoline engine like the Jeep 4.0. This high viscosity oil is a top-grade product from Mobil, a reputable brand.

What’s more? It is a fully synthetic oil that gives the engine a smooth performance under high temperatures. It provides sufficient lubrication while allowing a high level of thermal equilibrium. Also, its chemical composition prevents the build-up of residue within the engine.

Do you know why this oil is common in the automotive field? Well, thanks to its affordability and quality, Mobil 1 10W30 is worth every penny. Moreover, this oil is quite easy to be compatible with many kinds of vehicles.

Overall, It will not disappoint you with the outstanding thermal and oxidation stability.

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Best Oil for Fall and Winter – 5W30

5W-30 is the best oil grade for the Jeep 4.0 engine during the winter. When you switch off your engine during the winter, the oil will cool down and thicken.

When it’s time to start your engine in the morning, thick oil can’t circulate through the engine fast enough. That factor makes a thinner oil like the 5W30 perfect for the winter and fall.

Mobil 1 Advanced Full Synthetic Motor Oil 5W-30

Mobil 1 Full Synthetic 5W-30
Mobil 1 Full Synthetic 5W-30
This Mobil 1 5W30 provides excellent engine protection at low temperatures. If you are finding the oil which protects your engine for 10,000 miles, this 5W30 will be your best choice.

This 5W-30 motor oil will help sustain your engine’s performance under low temperatures (down to -30 degrees F).

Its lower viscosity will help to reduce timing chain wear and maintain a good fuel economy during the winter. It also prevents the build-up of sludge within the engine.

Besides, this full synthetic oil enables your engine to control the oil breakdown, which helps it run smoothly up to 10,000 miles or in 1 year.

Are you worried that your vehicle will get older and older over time? With its special formula, this Mobil 1 5W30 will blow your worry, which keeps your engine running like a new one.

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Feature #2: High Mileage Engine

High mileage oil is useful in old vehicles, especially jeep models that contain the 4.0 engine. High mileage oil will solve the challenges that occur on vehicles with 75,000 miles.

If you drive very often, go for high mileage oil. You will also need it if you use your vehicle to tow a trailer. It will reduce smoke, carbon emissions, and oil consumption on machines like the Jeep 4.0.

High mileage oil has chemical additives that stop any form of leaking within an engine. Most people are confused about whether they need it or not. Here are the signs to look out for:

  • If you notice an extremely loud engine noise, switch to a high-density oil, which is high mileage oil.
  • If you pack your car in a spot and notice oil patches on the ground, it is time to switch to high mileage oil.

Valvoline High Mileage SAE 10W-30

Valvoline High Mileage 10W-30
Valvoline High Mileage 10W-30
This product is well-known for its reliability. The Valvoline SAE 10W20 will maximize your engine lifespan over 75,000 miles due to its anti-wear film.

Well, I have owned a Jeep with 100,000+ miles on them and have used this High Mileage synthetic oil at 5,000 intervals. So that, I highly recommend this oil to you if you have 75,000 miles-vehicle. It has a thick and durable anti-wear film that prevents the engine from the breakdown.

In addition, it contains special antioxidants to keep your 4.0 engine running under the tightest circumstances.

It also comes with high-quality seal conditioners to prevent the formation of residues and sludge. The Valvoline SAE 10W-30 oil is a synthetic blend, which is a step higher if you use conventional oil.

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1. How Much Does A Jeep Wrangler Oil Change Cost?

The price of a Jeep Wrangler oil change costs US$93 to US$145. The cost varies from one location and model to another.

2. What Is The Jeep Wrangler Oil Change Interval?

Jeep Wrangler models from 2018 have a special indicator that tells you when you need an oil change. Ideally, you should change your Jeep Wrangler’s oil after every 7,500 to 10,000 miles

You could also check the owner’s manual of your Jeep Wrangler for a recommendation. The maximum period that you should drive a Jeep Wrangler without changing the oil is a year.

3. Can I Switch From One Oil Type To Another?

Yes. You can switch between conventional oil, synthetic blend oil, and full synthetic oil. You will need to change conventional oil more often compared to synthetic oil. Synthetic oil is also known to contain fewer impurities.

Final Thoughts

The engine doesn’t have any difficulty with maintenance. The condition to maintain vehicles with this engine is to use high-quality oil. This guide has exposed you to how viscosity ratings affect the kind of oil you should use. Thicker oil is better for the summer, while thinner oil flows better during the winter.

However, stick to the recommendations in this guide. We have selected them based on stringent and well-conducted research. Enjoy your rides, and remember that a good maintenance culture is the backbone of a long-lasting vehicle.

Read more: AT205 Reseal Vs. Blue Devil: Will These Oils Stop Leaking?


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