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An engine’s primary function is to provide the power required to make the vehicle move. This power is produced when the compressed fuel is ignited. In order to cause this ignition of the fuel, the engine is equipped with a small but very much needed component: The spark plug.
You might be aware of this significant part of the engine. What you may not know is that there is a wide variety of spark plugs in the market all with their own specifications. They each have different metal conductors and are classified mainly under these criteria.
To assist you to choose the most suitable for you, we will provide you the best spark plugs with reviews and comparison table.
Do you need strong evidence to replace your spark plugs?
The National Institute for Automotive Service Excellence indicates that bad spark plugs can decrease fuel economy by up to 30%, and can cost drivers up to about 94 cents per gallon at today’s prices.
If a car’s gas mileage suddenly drops, there’s a good chance it’s because of misfiring spark plugs.
You can check our picks in the table below and read corresponding spark plug reviews afterward.
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Best Spark Plugs – Reviews
You should never underestimate the benefits that come with replacing your spark plug from time to time. Luckily, this component is not too pricey to make you think twice about a replacement.
However, due to the extensive nature of the spark plug technology, it is a nearly impossible task to know just which type and/or brand is the best for your engine. Let’s have a look at some of the world’s best spark plugs brand and model to aid you in making the best decision:
NGK Platinum Spark Plug – Best Spark Plug for Gas Mileage
- Rating: 4.6 / 5
- Brand: NGK
NGK products are great for most vehicles. This specific spark plug is a top-notch laser platinum spark plug suited for small cars like the Audi and the Volkswagen.
The thing about platinum spark plugs is that they provide high ignition ability for a longer period of time compared to other electrode types. This is due to the slow decomposition rate of platinum, which makes it a really long-lasting metal. This increased durability makes this one of the best spark plugs for gas mileage.
You can always count on NGK to deliver quality, affordable spark plugs for any type of vehicle. It is due to this that their products are going to appear a number of times on this list compared to other brands.
What We Liked
- This spark plug is highly efficient. Its longer life span means that it can stay effective for longer
- Delivers a smoother idling compared to other spark plugs within the same price range
- Lowers emissions
What We Didn’t Like
- Does not improve performance as expected especially if the gapping is wrong
- Is a little more on the pricey side
ACDelco Professional Iridium Spark Plug
- Rating: 4.6 / 5
- Brand: ACDelco
An Iridium-tipped spark plug tends to be on the higher side when it comes to price due to the delicate features they possess and the added benefits that they offer.
ACDelco Professional Iridium Spark Plug is a high-end iridium spark plug made to last long. It is best for both performance engines as well as gas mileage. Although the iridium electrode may not be as long-lasting as platinum ground electrodes, there are instances where they match up pretty well.
This particular spark plug was designed for general motors and is an ideal replacement for today’s top-performing vehicles. However, it is still highly recommended that you confirm if it is for you otherwise you might end up investing blindly and lose your money.
What We Liked
- Outstanding lifespan reduces the need to change it every so often
- Better combustion compared to other spark plugs within the same price range
- Wear-resistant
- Incredible performance
What We Didn’t Like
- It is quite expensive compared to other spark plugs due to the iridium used
This is a spark plug with a nickel tip at the center electrode and a center copper electrode core. It thus falls into the copper spark plugs category due to the material used in its central core.
NGK really wanted to make this spark plug efficient and as such utilized a triple gasket design to eliminate gas leakage past the shell. It is one of the best spark plugs for fuel economy due to this triple gasket design.
This spark plug is most suitable for non-automotive vehicles such as golf carts, outboards, motorcycles, and ATVs.
What We Liked
- It is corrosion resistant
- High dielectric strength
- Has enhanced spark and heat transfer due to the pure alumina silicate ceramic insulator
- Has improved anti-fouling; all because of the corrugated ribs embedded in its design
- Quite easy to install
- Improves engine efficiency and increases the power output
What We Didn’t Like
- No cons
NGK Iridium IX Spark Plug –Â Best Spark Plug for Horsepower
- Rating: 3.5 / 5
- Brand: NGK
This is an incredible laser welded iridium tipped spark plug that is exceptionally durable and a must-have for high-performance engines. It is definitely best for performance engines and for durability. It provides an amazing amount of power to the engine by making optimum use of the air/fuel mixture. This makes it a suitable option for those seeking to increase horsepower. It is least likely to misfire or malfunction due to the slightly longer insulator nose than other spark plugs.
What We Liked
- Has a metal plating that resists corrosion and seizing
- It uses iridium and as such carries the added benefits of the metal, making it a great option for high-performance engines
- The long insulator nose prevents fouling
- A ribbed insulator prevents flashover
- A triple gasket seal prevents combustion gas from leaking
What We Didn’t Like
- The iridium is extremely delicate and might fracture
Autolite Double Platinum Spark Plug –Â Best Spark Plugs for Performance
- Rating: 4.5 / 5
- Brand: Autolite
Just as the name suggests, this spark plug offers platinum to platinum firing. It is extremely long-lasting as it utilizes not only platinum tips but also platinum center and side electrodes.
What We Liked
- The platinum to platinum firing improves performance and durability as it is also resistant to gap wear
- Central electrode fires quickly and cleanly for an easier startup
- Improves fuel economy
- Highly resistant to corrosion due to the nickel plating on the steel
What We Didn’t Like
- Has to be manually gapped
Autolite Platinum High Thread Spark Plug
- Rating: 3.9 / 5
- Brand: Autolite
This is a high-end spark plug with a sleek design. It is meant to increase the performance of engines while providing long-lasting service. Autolite came up with this design mainly for use with Ford engines to enhance performance, this platinum spark plug is best for 3 valve motors.
What We Liked
- Improves performance
- Solid steel construction minimizes corrosion effects
- Has a minimized gap erosion
What We Didn’t Like
- Difficult to replace without the right tools and you might break the electrode sleeve
This platinum spark plug by Bosch is one of the best spark plugs for fuel economy.
It offers the most efficient combustion as the ground electrodes provide easy access to the air/fuel mixture, making the process run that much smoother. The design featuring four-pronged ground electrodes ensures that the optimal amount of the air/fuel mixture is reached for combustion to occur.
What We Liked
- Fairly easy to install
- Greater power and efficiency because of its design
- Produces a powerful spark that causes your engine to run better
- Has a yttrium alloy that reduces oxidation, hence making it resistant to wear even at the highest temperatures
What We Didn’t Like
- No cons
Spark Plugs – The Buyers Guide
If your car is your pride and joy, you will most definitely want nothing but the best for it. This means that while tuning it up, you will want to have the best spark plug in order to avoid a misfire and the dangers that come along with it.
Having reviewed the best spark plugs above, you’re probably wondering which one would be the best for your engine. As stated earlier, there are notably different models of spark plugs as there are different makes and models of cars. As such it is essential that you understand the different specifications for both your car and the spark plug you intend to buy.
The best way to know which spark plug suits you is to check your owner’s manual for the manufacturer’s advice.
Nonetheless, here are the things you need to watch out for when selecting a spark plug:
1. The make and model of your car
This is the essential requirement as spark plugs are developed in different countries, just like cars, and as such have different specifications of the make and model for which they can operate. This information also includes the model year that your car was manufactured.
2. Type of engine and number of cylinders
Having this knowledge will help you to determine if a certain spark plug will provide a spark sufficient enough to ignite the air/fuel mixture in your engine.
3. Engine displacement
This refers to the amount of room in each cylinder when the piston is at its lowest point. It is important to have this information as it helps you determine what length of spark plug you will need to ignite the fuel in your engine.
4. Fuel system
You may need to know the fuel system that your car has as some spark plugs can only operate in specific fuel systems efficiently.
5. Spark plug gap
This is the space that is required between the center and side electrodes of each spark plug.
6. The part number of the spark plug designed for your vehicle
If you have a custom-made engine, or if your engine has had a number of tune-ups and modifications such that you are unable to fully trust the owner’s manual, you may need to observe the following about the spark plug:
- Thread reach
- The thread diameter
- The insulator nose projection
- Whether the spark plug incorporates a gasket or is of the conical type
If you are ever in doubt, there is a lot of information online that can assist you. Also, you can contact experts for advice on which spark plug is best suited to replace your old one.
Never let a misfire ruin your engine, get the best spark plug for your car and feel the difference it makes.
Spark Plugs FAQs
1. How do Spark Plugs work?
Think of a lightning bolt as a spark. This would mean that the air in between the ground and the clouds is a large gap that would require the electric current to have a really high voltage in order to cross the gap.
The spark plug is also so equipped with a gap and when a high voltage of about 15000 volts is passed through it, the current crosses the gap causing a spark to form. It is this spark that ignites the fuel, causing it to release a significant amount of energy to power up your vehicle. That is, in a nutshell, the functioning of a spark plug.
2. Which is better? Platinum vs. Iridium vs. Copper Spark Plugs
Before jumping to the conclusion that any of the three mentioned types is the best spark plug, it is important for you to be aware of the aforementioned selection criteria when choosing a spark plug.
Copper spark plugs have a relatively large diameter electrode. This means that it requires more voltage than the others to produce a spark. The Nickel alloy used is also significantly softer than platinum or iridium and this makes the sharp firing edge you get from the box wear out quickly.
With all this insight, copper spark plugs are best for older model vehicles that have low voltage distributor based ignition. Using them in other ignition systems will lead to fast wearing out. However, if your owner’s manual specifies that you use copper spark plugs, it is advised that you do not upgrade to the other types.
Platinum spark plugs are best for vehicles with an electronic distributor based ignition systems. There are single platinum spark plugs that have the platinum disc welded to the tip of the center electrode while double platinum spark plugs are considered to be twice as better.
Platinum spark plugs prevent spark plug deposit buildup and fowling by running a bit hotter than other spark plugs. If your owner’s manual recommends that you use a platinum spark plug, it is advised that you stick to it.
Iridium spark plugs are undoubtedly the best ones around and can last about 25 percent times longer than platinum spark plugs. They are also relatively expensive compared to the others. Their firing efficiency is fairly high due to the fine wire center electrode. Despite their price, it is recommended that you stick to iridium spark plugs if your owner’s manual suggests it.
3. How often should spark plugs be replaced?
The question of when to replace spark plugs is dependent on a number of factors, misfiring being among them. However, the best rule of thumb is to replace them before the recommended service interval as this enables you to stay ahead of any possible issues that can arise when you delay replacing.
Also, being early, allows you to remove it before it seizes the cylinder head. In the economists’ view, the wear that occurs in the final moments of a spark plug’s life will cost you a lot more in gas mileage compared to a set of new spark plugs.
4. What are the symptoms of a misfiring spark plug?
If you are not keen on your mileage track record, you can still know if your spark plug is due to be serviced or replaced when you see the following signs:
- The engine idles roughly. The engine should have a smooth and constant sound. If it makes any more noise than usual, it might be time to have it checked.
- If you’re having trouble starting your car in the morning, it might be due to a dirty spark plug.
- Your car’s engine misfires due to built-up carbon deposits on spark plugs.
- Engine surge or hesitation.
- Worn spark plugs can lead to high fuel consumption.
- If you experience poor acceleration, it might be time to install fresh spark plugs.
5. Are all spark plugs pre-gapped?
Not all spark plugs are pre-gapped. This is because one spark plug can fit multiple engines and different engines require different plug gaps. As such, some plugs are sold without being pre-gapped and, depending on your engine’s specification, you are required to gap them before you install them.
6. Can spark plugs be cleaned?
The short answer is yes. Spark plugs can be cleaned using a wire brush or spray on the plug. Watch this video on how to clean spark plugs.
The detailed answer is, it is not recommended to clean a spark plug because the efficiency of a cleaned spark plug is considerably lower than that of a new one because electricity discharges better form a sharp edge than from a blunt one.
7. What does a bad spark plug look like?
The image below is a clear contrast between a bad spark plug and a good one. The one on the left is bad and the one on the right is in perfect state.
Typically, a bad spark plug has black or heavy ash deposits around or on top of the center electrode. This deposit leads to the poor performance of the spark plug.
Conclusion
We did our best for you to make the optimal choice in search of the best spark plugs on the market. Here are our top choices:
1. Best Spark Plug for Gas Mileage – NGK Platinum Spark Plug
2. Best Spark Plug for Performance – Autolite Double Platinum Spark Plug
3. Best Spark Plug for Horsepower – NGK Iridium IX Spark Plug
Do not ever underestimate your engine problems, small and cheap parts like spark plugs can make great differences. The difference pays off really quickly.
