Spark plugs are small devices that are used in any gas powered vehicle. They can be found in automobiles, lawn mowers, and even go-carts. They are an important piece of the ignition system that allows the combustion of the engine to occur. Most vehicles require you to have one spark plug per cylinder, which means that many of the vehicles on the road require either four or six spark plugs to run properly, but which of the spark plugs on the market is the best option for your car?
We have taken the time to research the different spark plugs that are available for purchase and after a thorough testing of each product, we choose several of the best options to review in this guide. Before we start looking at specific spark plugs, let’s take a look at the different types of spark plugs that you can purchase.
Types of Spark Plugs
- Copper Spark Plug
This type of spark plug is typically referred to as a standard version of a spark plug. The reason that these variations shine is that the copper on the device is great for conducting the electricity; in fact, it is the best conductor that you can have on a spark plug. If you are looking for an efficient spark plug, the copper tipped plugs are the best option. Since the electricity is easily conducted, the spark plug will not overheat as quickly, which means that the life of the spark plug will be extended. Copper does naturally erode, so the lifespan of this type of spark plug will always be limited, which is why they are often very inexpensive to purchase. These copper tipped spark plugs will typically last between 20,000 miles and 40,000 miles before a problem arises.
- Platinum Spark Plug
Platinum is a metal that is a little less conductive than copper, which means that it could possibly become overheated as you are driving down the road. When a spark plug overheats, you are not in danger, but the vehicle will not perform as well because the connection is not as solid as it could be. These spark plugs tend to cost a little bit more than copper ones, even though they will not conduct as well, they tend to last a lot longer. The metal does not erode away with daily wear and tear; in fact, the life of a platinum tipped spark plug is nearly double that of a copper one. Most can even last for up to 100,000 miles of use. If you are looking for a spark plug that will get you as far down the road as possible, then choosing a platinum tipped one may be beneficial for you.
- Double Platinum Spark Plug
A double platinum spark plug has the same longevity that you get with a single platinum spark plug; in fact, since this variation has two plates on the tip, it will typically have an even longer life. The conductivity issue still remains though because platinum is not a great conductor of electricity. This variation is basically an improved version of the platinum. It offers a slightly better performance that you can take advantage of for a slightly higher price.
- Iridium Spark Plug
Iridium spark plugs are made from a less conductive material than copper, so even though they perform decently, they do not work quite as well as the standard variation of the spark plug. Since the material is more durable, the spark plugs do tend to last from between 40,000 miles to 60,000 miles. These iridium tipped spark plugs are typically the most costly of the four types because it is a rarer material to get, but the dependability of these spark plugs make them a great option for long term use.
The Heat Range of a Spark Plug
The heat range of the spark plug is the amount of time that the heat combustion takes to damage the spark plug. The heat rating is important because hot spark plugs can affect your driving and towing experience by causing the engine to knock. A cold spark plug means that the combustion process may not be able to complete, which means that carbon can build up on the unit and cause corrosion to occur at a faster rate.
What is Gapping?
When a spark plug erodes, specifically a copper spark plug, the distance between the tip and the curve will increase. Gapping is the process that you do to close the gap so that you can increase the potential power of the spark plug and reduce the amount of fuel that your vehicle is using. Gapping will help prevent misfires from occurring, and it will also increase the lifespan of the part.
Best Design Feature
Autolite 104 Copper Resistor Spark Plug
It is designed with a full copper core, which is great for heat transfer and conductivity.
Denso (3297) SK20R11 Iridium Spark Plug
The iridium tip has a high melting point so overheating should not be an issue.
NGK (6953) BKR5E-11 V-Power Spark Plug
This device combines a solid copper core and a nickel tip to create the best combination of conductivity and longevity.
ACDelco 41-993 Professional Iridium Spark Plug
It offers great engine stability when you are idling your vehicle.
NGK (7092) BKR6EGP G-Power Spark Plug
The laser welded tip requires reduced voltage to maintain a consistent spark.
1) Autolite 104 Copper Resistor Spark Plug
The first spark plug on our list is the Autolite 104 Copper Resistor Spark Plug. It is designed with a copper-glass seal that is designed to bond the electrode tip and the post together. This makes sure that when you start your vehicle, you get the voltage that it requires. In addition, during our testing phase, this seal proved to be completely leak proof, which means that it will be able to perform in all weather conditions without being sacrificed. This plug is also designed with a steel shell to add an additional layer of protection.
Around the center, you will notice a ribbed insulator that is placed around the copper core to help prevent misfires from occurring. Since copper spark plugs do not tend to have a long life, the center of this product was created with a high nickel alloy material to help extend the life of the spark plug. As we ran these spark plugs in our test vehicle, it was easy to see that the spark plug was able to quickly start the vehicle without any issue. In addition, the acceleration was extremely smooth and the gas mileage that we experienced was optimized by quite a bit.
2) Denso (3297) SK20R11 Iridium Spark Plug
The next spark plug that we felt belonged on this list is the Denso (3297) SK20R11 Iridium Spark Plug. Whereas the first one on our list was copper tipped, this one feature an iridium tip, which means that it has a much longer lifespan. In fact, iridium is six times harder than platinum, and our tests indicated that it is actually about eight times stronger and more durable as well. Because of this extreme strength, the electrode on the spark plug will not wear over time like it would on a copper plug. In fact, extremely high heat that will be present in extreme driving situations will not even cause damage and wear to the device.
The one downside of this product is that the iridium is not as great of a conductor as the material in the last spark plug that we reviewed, so even though it will still perform great, it may not be on par with the copper spark plugs that you are accustomed to. The acceleration and the overall performance will still be top notch, and during times when the car is idling, the combustion of the plug will remain stable.
3) NGK (6953) BKR5E-11 V-Power Spark Plug
The NGK (6953) BKR5E-11 V-Power Spark Plug is the next product on our list because it is a reliable option that will last for miles of use. It is designed to operate over a wider heat range than many of the spark plug options on the market so that means that the spark plug will not become damaged in extreme racing situations where it would have the possibility of overheating. When we placed these spark plugs in our vehicle to test them, it only took about 20 minutes to notice that the improvements in the ability to start with ease and the fuel efficiency while driving was greatly improved.
We really liked the triple gasket seal that is present on the device because it eliminates the chance that a gas leak could occur. The unit is designed to have a great heat transfer rate that will help prevent corrosion from building up around the nickel tip, and the copper core provides a superior means of conduction. During our testing phase, we really liked the Trivalent Metal plating that is seen on the outside of the spark plug because it creates a great anti-corrosion surface that will extend the life of the NGK (6953) BKR5E-11 V-Power Spark Plug.
4) ACDelco 41-993 Professional Iridium Spark Plug
The next product on this list is the ACDelco 41-993 Professional Iridium Spark Plug. It is another iridium spark plug, so you can expect that it will have a long lifespan, but this spark plug also performs at an improved rate from most spark plugs on the market as well. We noticed that the engine was very stable when the car was idling, and the performance on the road proved that this is one of the best spark plug options available. The iridium that makes up this spark plug is one of the toughest on the market, so the durability that it provided during years of inclement weather will also not cause any corrosion or wear to the surface.
The unit is designed with electrodes that are more efficient for starting a vehicle in cold weather. During our tests of these spark plugs, we found the acceleration to be quicker and the fuel efficiency to be better than with the original spark plugs that were in the vehicle. The electrode is designed to burn away carbon deposits that form on the tips, which will improve the overall gas mileage that you get in the vehicle.
5) NGK (7092) BKR6EGP G-Power Spark Plug
The final product on our list is the NGK (7092) BKR6EGP G-Power Spark Plug. It is a platinum tipped spark plug that is designed to give you a lot of use and performance. During our tests of this spark plug, we noticed a higher level of fuel efficiency and a quicker starting rate, even in cold weather situations. The tip is designed to create a level of combustion that is stable and consistent, which means that it will not have issues maintaining the voltage connection. Most spark plugs of this type last for a good 60,000 miles, but we have determined that this one can actually exceed that estimation by a few thousand miles at least.
The unit is designed with trivalent metal plating that helps to prevent the tip of the spark plug from becoming corroded over time, so that means that the lifespan of the product can be even longer. We also liked that their unit comes with a triple gasket seal to prevent gas leakage during the combustion stage of starting your vehicle. These spark plugs do not have a lot of additional frills, but they are a very effective choice that can be purchased at a relatively low price point.
Spark plugs are a crucial component for vehicles, so you will want to purchase the best spark plugs on the market to give you the best mileage, performance, and longevity. As you have seen, copper tipped plugs are the best performance wise, but they do not last near as long as some of the other types. So, which of the products that we reviewed are the best spark plugs?
If we were to pick one of the options that we reviewed, the NGK (7092) BKR6EGP G-Power Spark Plug would come out on top. It is a well-rounded spark plug that is designed to improve the performance of your vehicle as well as be durable enough to last a long time without needing to be replaced. Spark plugs are not the most expensive items to purchase, but the best bang for your buck option on our list is the NGK (6953) BKR5E-11 V-Power Spark Plug. They are sold for less than three dollars per spark plug, and each one combines a copper core and nickel plating to optimize performance and extend the life of the product.