Best Spark Plugs for 4.0 Jeep – Choose only the best for your vehicle

Best spark plugs for 4.0 jeep (1)
Best Brand
NGK V-Power
Our Top Pick
Champion RC12ECC
Value for Money
Autolite XP985

Spark plugs are the perfect examples of “small things, big punch.” 

They are among the most essential components in a car because without them, you wouldn’t be able to start your car properly! They also eliminate heat from the combustion chamber and keep the vehicle cool. So, if your spark plug isn’t functioning properly, you will know immediately. And, this is something you shouldn’t procrastinate. A bad spark plug is dangerous! Make sure you buy the best replacement spark plugs immediately. 

Product No.Spark Plugs for 4.0 Jeep
Product ImageProduct ReviewsCheck Price
1)NGK V-PowerNGK_V-Power5BuyOnAmazon
2)Autolite XP985Autolite_XP9854.5BuyOnAmazon
4)Champion RC12ECCChampion_RC12ECC4.5BuyOnAmazon
5)NGK 3459NGK_34595BuyOnAmazon
6)Champion Copper PlusChampion Copper4.5BuyOnAmazon
7)E3 Spark PlugsE3 Spark Plugs4.5BuyOnAmazon
8)Mopar OEMMopar OEM4BuyOnAmazon

Now, one point to remember here is that every jeep has different sets of spark plugs that you must buy. In this article, we are going to speak about the best spark plugs for 4.0 jeeps because we are getting a lot of questions about them. Let’s start.

Best Spark Plugs for 4.0 Jeep

1. NGK V-Power Spark Plugs (6 pieces)


The NGV spark plugs were made specifically for jeep models between 1997 and 2006. They are ideal for the L6 engine kit setup. Here are a few things you should know about these spark plugs:

  • They are very easy to install thanks to their insulator design and corrosion-resistant plating. You can remove them just as easily as well, when the need arises.
  • The spark plugs are durable and resist damage to a large extent as they have cold-rolled threads on the cylinder head. The metal plating that’s trivalent further helps this cause as it promises anti-seizing and anti-corrosion properties.
  • They have a five-rib insulator that avoids flashover and leakage. These features are very important because they prevent leakage and misfires.
  • They also boast of a broader heat range, better conductivity, and superior heat dissipation. 
  • The manufacturers promise better performance than standard and OEM spark plugs. This is why we recommend them as well. 

buy @ amazon

2. Autolite Iridium Spark Plugs for 4.0 Jeep


If you just need 1 spark plug and aren’t really looking for multiple pieces, we recommend the Autolite Iridium Spark Plug. It is available as a single plug or as packs of 4, giving you complete freedom to choose. Below are a few of its features:

  • It is made of a platinum alloy and has a 0.6mm fine wire center electrode. This is a huge USP because it directly enhances its ability to ignite.
  • The side wire technology that’s used on the spark plug is crucial as well because it resists general wear and tear.
  • It has been designed to promise durability and zero gap erosion. This makes sure that the spark plug lasts long and works well. Even the tip is plated with platinum.
  • It lives up to the OEM standard of function and design. You, in fact, won’t feel a difference between the standard plugs and this one.
  • The spark plug comes with a terminal nut and a motor seat gasket.

buy @ amazon

3. NGK V-Power Spark Plug (6 pack)

NGK V-Power

This set of NGK V-Power spark plugs is for Jeep Grand Cherokee models that were manufactured from 1999 to 2004. Let’s check out why you should buy these plugs:

  • The spark plugs fit L6 engines of the size 4.0/242. You can use them with any engine of the engine family AMC inline 6-cylinder.
  • It comes with excellent features such as lower emissions and good fuel economy.
  • It also has anti-seizing and anti-corrosion properties because it has a trivalent metal plating.
  • You can rest assured that it will stay safe even when exposed to chemical water and electrical water.
  • It also improves acceleration performance.
  • Other features are low voltage requirements, better ignitability, and great anti-fouling levels.
  • The tip of the electrode is made of a nickel alloy.

buy @ amazon

4. Champion Copper Plus Spark Plug

Here’s an Amazon’s Choice product that you will definitely love! The Champion Copper Plus Replacement Spark Plug is available as a pack of 1 for specific vehicles. Make sure you check compatibility before buying it. Also, please gloss through its features:

  • The electrode has a copper center. This controls Championthe heat range very well and ensures that the spark plug works well for a long time.
  • It comes with a patented ultra-seal coated shell that makes it resistant to corrosion.
  • It has been built keeping ISO and SAE standards in mind, especially when it comes to performance. So, you can be sure that it works well.
  • The semi-conductor resistor functions to give you the best RFI and EMI suppression.
  • These spark plugs have the ability to achieve the right temperature quickly and stay stable regardless of the engine load.
  • Please keep in mind that the plugs are not pre-gapped.

buy @ amazon

5. NGK 3459 Spark Plugs for 4.0 Jeep

NGK 3459

We haven’t come across anything negative about NGK spark plugs so far. All their products are of top quality and deliver what they promise. These particular spark plugs are the same. They live up to all expectations! Let’s find out more:

  • They fit all 4.0L jeeps, but we recommend that you check the model before making a purchase.
  • They have corrugated ribs that avoid flashover.
  • The insulator is made of alumina silicate ceramic. It ensures excellent heat transfer and great strength.
  • The spark plugs have triple seals, thanks to which you don’t have to worry about leakage at all.
  • The core, which is made of copper, works to remove excess heat.
  • You don’t have to worry about seizing or corrosion at all! This is because the spark plugs have trivalent metal plating.

buy @ amazon

6. Champion Spark Plug – Plus 412 

Champion CopperThe Champion Plus spark plug stands up to its name. It is known for its durability and performance. It is one of our favorite options for multiple reasons. We have mentioned a few for you here:

  • This is a copper spark plug, which means that the center electrode has a copper core, which provides excellent control of the heat range and extends its life.
  • It is highly resistant to corrosion thanks to its patented Ultraseal coated shell.
  • The spark plug also has a patented SAC-9 semiconductor resistor.
  • You will experience easier starts and fewer engine misfires once you install these spark plugs.
  • They are exact factory replacements and will improve your mileage.
  • The only thing you should remember here is that they don’t come pre-gapped. You must gap them correctly based on your requirements before installing them.

buy @ amazon

7. E3 Spark Plugs 

E3 Spark PlugsThe E3 Spark Plug is unique and stands out from the rest in that it has a DiamondFIRE electrode that enables it to optimize heat transfer. It has many other features as well, which we have explained below:

  • The spark plug has been designed to serve multiple applications including reducing fuel consumption by 4-5%, improving the power by around 4%, and lowering hydrocarbon emissions.
  • The DiamondFIRE ground electrode works to increase turbulence and maintain adequate heat transfer at all times.
  • It has been designed keeping cold heat range in mind to ensure that it is more durable. It also contains a yttrium alloy that works to reduce temperature in the side wire.
  • The terminal is plated with nickel.
  • The spark plug is guaranteed to perform well for 100,000 miles or 5 years.
  • Other benefits of installing these spark plugs are reduced emissions, faster starts, and longer life.

buy @ amazon

8. Jeep Wrangler, Grand Cherokee 4.0L Spark Plugs

Mopar OEMThese spark plugs from Mopar has been specifically designed for Jeep Cherokee, Jeep Grand Cherokee, and Jeep Wrangler. However, we advise you to check the model numbers before making a purchase. Here are a few features of these spark plugs:

  • They are OEM quality spark plugs. This means that will perform just like your original spark plugs or exceed that performance.
  • They are pre-gapped, which means you can install them straight out of the box. However, as a precaution, it is always ideal to check the gap before installation.
  • The center electrode has a V-groove that optimizes flame expansion.
  • Since these plugs were designed specifically for Jeep models, you can expect factory performance.

buy @ amazon

The importance of spark plugs

We always speak about spark plugs and the importance of buying good quality ones. But, have you ever wondered why spark plugs are so crucial for the health of the engine? What is their purpose? Here’s your answer –

In order for the engine to start, it needs a spark because the air and fuel mixture needs to be ignited. The spark plug provides this spark. 

So, if the plug wears out, you will have difficulties starting the engine. Performance and fuel economy will also suffer. If you continue using the vehicle, the engine will bear the consequences and ultimately fail.

When should you change the spark plug?

If you see any of the following signs, you should consider changing the spark plug:

  • Bad fuel economy – Worn-out spark plugs can cause you to burn around 30% more fuel than usual.
  • Engine misfires – This is the biggest and most obvious sign that your spark plugs need to be replaced.
  • Rough idling – Weird sounds and unfamiliar vibrations indicate that there’s a problem. Sometimes, it’s as simple as a dirty spark plug that needs to be cleaned. Other times, it is much more than that.

People also ask

1) How many spark plugs does a Jeep have?

This depends on the model and the number of cylinders. Usually, it is 6 spark plugs for 6 cylinders (V6). But a few models have 4 (V4) and 8 (V8) cylinders. They will require the same number of spark plugs.

2) How much are spark plugs for Jeep?

If you buy only the plugs and install them yourself, they will cost around $70, depending on the type of spark plugs you choose. Labor costs are usually around $100. 

3) What is the spark plug gap in Jeep?

It is around .035.

4) What happens if a spark plug gap is too big?

The plug won’t fire at all, in most cases. In other cases, it may ignite sooner than required. Both of these are undesired and best-avoided situations.

No matter which spark plugs you choose from our list, you will have made the right choice! But, to ensure that you pick only the best one that suits your needs, please make sure you compare the options above before adding one to the cart.

If you have any doubts regarding any of the products we listed, please do not hesitate to contact us. 

Francis Ceron

About Francis Ceron

Did you know the major cause of car failures are due to spark plugs. At sparklplugs guru you wil find all the necessary reviews, guides and facts to improve the performance of your vehicle and have a smooth functioning.

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2 thoughts on “Best Spark Plugs for 4.0 Jeep – Choose only the best for your vehicle

  1. Avatar Charles Long says:

    Wow, What an Outstanding post. I found this too much informatics. It is what I was seeking for. I would like to recommend you that please keep sharing such type of info.If possible, Thanks.

    1. Naomi Naomi says:

      Thank you so much for your kind words! 🙂

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