Spark plug wires are arguably just as important to the proper functioning of the engine as spark plugs themselves.
They are responsible for the transfer of voltage from the distributor to the spark plugs, which will then use that voltage to ignite the mixture of air and fuel in the combustion chamber. Sure, there are some modern automobiles that take advantage of distributor-less ignition system, where the spark plug wires connect the spark plugs directly to coil packs, while other automobiles use a coil-on-plug model that doesn’t even need a spark plug wire.
However, these are still novelties and the majority of vehicles use spark plug wires.
Spark plug wires have one thing in common with all the other components in your engine: they wear down with time and use and you will eventually have to replace them. And so it is imperative that you not only know a little about how to choose your next spark plug wires, but also about which ones are the best in the market. We’ve got you covered on both fronts.
ACDelco is a pretty diverse manufacturer, offering a wide range of different spark plug wire sets that deal with many different vehicles and applications.
The most popular of these is the Professional wire set, which contains fiberglass on the inside and a silicone jacket on the outside for maximum performance and durability.
- Wire conductor, diameter and length are optimized to deliver maximum spark with high protection
- The distributor is boot shaped and made of optimal materials to fit properly, install easily, and provide water-tight seal
- The terminal is designed to assist installation and spark plug retention
- High dielectric materials are employed in the insulator
This wire set is engineered for maximum performance and durability. It contains fiberglass for enhanced strength and silicone insulators that are resistant to high temperatures.
The length of the wires, the conductors used inside them, and the diameters have been specifically optimized to deliver maximum spark.
The spark plug distributor boot is made of the right materials and shaped in such a way as to provide proper fit and water-tight seal while being super easy to install.
What Customers are saying
- They’re very nice looking and fit so tight that they can actually be hard to take out again.
- I love the performance boost too!
MSD is another company that is highly respected in the industry and offers a plethora of ignition products, ranging from coils and distributors to ignition boxes.
They also have a wide array of spark plug wires, including the 8.8mm, the Extreme 9000 ceramic, the Spiral, the Ferro-Spiral, the ThunderSport, the Super Stock, and the 8.5mm that we are reviewing here.
- The resistance value of the copper allow conductor is less than 50 ohms per foot
- The core is ferro-magnetic impregnated, which leads to high RFI resistance
- Outer sleeve is highly durable and is made of a proprietary material that has high resistance to abrasion and heat
- Terminals are made of stainless steel with dual crimp tabs that grip outer jacket and wire conductor separately
This spark plug wire set might be one of the pricier ones on this list. However, it has many great features that make it worth every penny. The 8.5mm copper alloy is definitely one of them.
The core is ferromagnetic impregnates and wrapped in 40 feet of copper allow conductor, making it very effective at suppressing RFI.
The outer sleeve is made of DuPont Kevlar, which has very high tensile strength and is resistant to abrasion and heat.
The terminals are made of stainless steel and have dual crimp tabs that grab the wire conductor and the jacket separately.
What Customers are saying
- Love them! They fit my GMC Sierra 5.3 LH6 (2007) perfectly and significantly boosted performance.
This simple set of 4 spark plug wires does the job well and is pretty easy to install. Each wire is color-coded and numbered to make installation easy. They also deliver very high performance.
- Has variable pitch winding that delivers very low resistance and RFI cancellation.
- The wires have a stainless steel terminal that is resistant to corrosion and positive locking for a tight fit and resistance to separation and vibration.
- The outer jacket is made of silicone that is tolerant of extremely high temperature above 250 degrees Celsius or 482 degrees Fahrenheit.
- The wires are each color coded and numbered to make for fast and easy installation.
NGK happens to be one of the largest manufacturers and suppliers of spark plugs, spark plug wires, air/fuel sensors, and oxygen sensors both in the USA and around the world.
Most of their products are therefore quite popular among vehicle owners. NGK spark plugs are designed specially with superior conductivity and noise suppression in mind.
The wires use either silicone or EPDM as covering for their high resistance to damage by chemicals, oil, and heat.
Each wire also has a stainless steel terminal end that is resistant to corrosion and positive locking, ensuring a tight link.
What Customers are saying
- Bought them for my car (1998 Honda Civic EX Coupe). They are extremely easy to install and boost the acceleration, especially when going up-hill.
- I love the quality and the price point too!
This spark plug wire set is a testament to Edelbrock’s reputation in the ignition industry as a high quality company with high quality products.
They deliver very high performance while remaining affordable and efficient.
- Extremely high RFI suppression
- Made from high quality materials for ultimate performance
- Silicone jacket is 8.5mm in diameter and resistant to heat, chemicals, moisture and abrasion to protect Kevlar spiral core.
- Delivers 40 ohms of resistance per foot for high voltage delivery and RFI suppression
The RFI suppression in these spark plug wires is extremely high, with a very low resistance of 40 ohms per foot.
The core in turn is protected by an 8.5mm silicone jacket on the outside that is resistant to heat, abrasion, moisture, and chemicals.
Overall, the materials used in the manufacture of these wires are of the highest quality to allow for top performance at all times.
What Customers are saying
- Great quality wires! Couple buddies at work already ordered them up too. Great price for excellent wires.
- Good wires, Sturdy and reliable. Installed about 100 miles ago. Just needed a tune up on my 2010 Sierra 5.3l engine.
The Different Types of Spark Plug Wire Sets
You probably know just how important spark plugs are to your engine and how, if you want your engine to run properly, you’re going to have to replace your spark plugs on a regular basis.
That’s all good, but what about the spark plug wires?
When it comes to sets of spark plug wire sets, there are 3 main types:
- The Distributed Resistance Spark Plug Wire
The most defining characteristic of this particular wire set is that it consists of fine strands of carbon bonded with fiberglass. This material has a very high resistance. There is an advantage to that high resistance, especially for vehicles where a lot of computers and electronics are involved in the running of the engine. That resistance reduces radio frequency interference, or RFI.
RFI won’t affect the reception on your radio, so you don’t really need to worry about it on that front. However, it is strong enough to interfere with the array of computers and sensors that are involved in the running of your engines. As a result, RFI can also indirectly interfere with the passage of voltage from the distributor to the spark plugs.
Having wires with high resistance helps since the thwart the RFI and keep your electronics functioning properly.
The distributed resistance spark plug wire set is quite common with American cars, and most of them are compatible with this type of wire set.
- The Inductance Style Spark Plug Wire
This type of wire set was mostly designed for Japanese cars. The inductance style plug wire consists of a spiral core that has a wire wound around it made of either nickel alloy or copper alloy. This is intentional, as the winding of the outer wire around the inner spiral core creates an electromagnet that thwarts RFI and allows electronics in the engine to function effectively.
While the inductance style plug wire blocks RFI like the distributed resistance wire, it has a much lower resistance than its counterpart. Again, this is an advantage, given the specific context within which this wire type operates.
It means that you won’t need a substantial current to bring power to the spark plugs when you’re starting the engine or running it. That makes them quite efficient.
- The Fixed Resistance Spark Plug Wire
This type of spark plug wire is found most commonly in European cars. It consists of copper wires or steel wires and has plug boots that contain resistors.
It works roughly the same as the inductance style spark plug wire, with only minor differences.
Considerations about the Spark Plug Wires you already own
Something you have to consider when you’re buying spark plug wires is the set of spark plug wires that your vehicle already has. This is because of compatibility.
Different cars will generally have different spark plugs, which directly affects the type of wire sets they will accept since each wire set will fit over certain kinds of spark plugs. Just look at the spark plug wires you already have on your vehicle and use that to inform the ones you will buy.
Also, remember that most spark wires are sold as a set. That means you should get the right number of wires for your vehicle.
There isn’t much to worry about here, since as long as the spark plug wire set is compatible with your vehicle it will come with the right number of wires. However, it doesn’t hurt to check your engine and count how many wires there are in your current set so you know what to look out for when getting the new set.
You should also make considerations about the length of the wire. Are the wires long enough to install securely in your engine? You should compare the new product’s length to the length of your factory wires as soon as you get delivery of the product. Just lay them out and compare them to the new ones, remembering which wire goes where. Once they match, installation is pretty easy.
Considerations about the Brand
You should also consider the brand of the spark plug wires if you want quality products. All of the brands listed here are reputable ones, so you don’t have to worry about quality. However, you should generally choose the brand that you are most comfortable with. If you own a BMW and love everything about BMW, then you should consider getting spark plug wires manufactured by BMW or supported third parties.
It can certainly be tempting to buy high performance spark plug wires. However, they have their pros and cons.
They are certainly very good and boost the performance of a car. However, they may not be very effective at blocking out RFI.
They are thus good for racing cars and other vehicles with few electronics but not necessarily good for the average consumer car that is full of electronics.
When is it Time to change your Spark Plug Wires?
There are a few signs that will tell you it might just be time to replace your spark plug wires. These include the engine being hard to start, having rough idling, accelerating slower than usual, consuming more fuel than usual, hesitating, and sputtering.
Of course, a disclaimer is due at this point.
While the signs listed above can be indicative of faulty spark plug wires, they can also be indicative of fault in a whole host of other engine and general car components. In order to ascertain without a doubt that it is, in fact, your car that has the issue, you should test your spark plug wires for faultiness.
How do you test your Spark Plug Wires?
Generally speaking, there are 4 ways you can test your spark plug wires to see if they are faulty.
This is the easiest way to test your spark plug wires without having to use any tools. Just perform a visual inspection of the wires, especially around the plug end boots since they are typically the first to fail.
Use your fingers as well by running them along the length of the wires to feel for cracked or exposed areas and brittleness.
If your spark plug wire is soaked in oil it is recommended that you replace it.
Faulty spark plug wires are known to leak electricity, so testing them for such leakage is a reliable way to determine if they need replacement.
A leak test is best carried out after a visual inspection does not yield any useful information.
All you have to do is wait until it is completely dark and then pop up the hood of your car and run the engine.
If your wires are leaky then you see lightning bolts jumping from the wires to whatever metal object is nearby. This is definitely a sign of trouble and means you should replace the offending wire set immediately.
Another way to test your spark plug wires for damage is to induce leaks yourself to see if they’re there. This one is a little complicated and might not be safe, so it’s best to let a trained expert do it.
You’ll need an insulated screwdriver or a grounded jumper wire.
Make sure whatever you use is grounded and insulated or else you will be running a high risk of electrocution. After all, you are dealing with high voltages here.
Whatever tool you end up using, run it along the length of the wire and watch out for arcs (electricity jumping to the tool). You will either hear them as crackles or see them as lightning bolts. This is a sign that your wires are faulty and need immediate replacement.
This method requires an ohmmeter. You can use the ohmmeter to measure the resistance of the spark plug wire. Measure each wire individually and check if its resistance falls within the range recommended by the original manufacturer.
If the resistance far exceeds this range, then the wire is faulty and needs immediate replacement.
Is there a difference in spark plug wires?
Yes, there is a difference in the different types of spark plug wires, depending on the technology they use and the vehicles with which they are compatible.
Be careful to check which spark plugs your vehicle is already using and which ones are recommended by your vehicle manufacturer to avoid getting the wrong spark plugs.
Should I replace spark plug wires?
Yes you should. Like any other car components, spark plug wires get worn out and damaged with time and need replacement. Read our buyer’s guide up-top to find out how to know if it’s time to replace your spark plug wires.
How often should you change your spark plug wires?
It depends on the spark plug wires and your intensity of use. There isn’t a fixed universal timeline for how long you should use a set of spark plug wires before using them. The best way to know is to test them regularly for faultiness, as outlined in our buyer’s guide up-top.
Which spark plug wires are the best?
It depends on the vehicle you are driving. Ideally, you should go for OEM spark plugs, though there are many aftermarket spark plug wires that are just as good. If in doubt, stick to your OEM or any supported third party brands.
Do spark plug wires add horsepower?
No, they do not. You may notice a significant boost in performance, but that’s only because your previous spark plug wires were so worn out that anything slightly better feels like a massive improvement.
What’s really going on is that new and high quality spark plug wires enable your vehicle to perform at the capacity it was originally meant to.
A good set of spark plug wires can drastically improve the performance of your engine by ensuring that enough voltage is delivered to the spark plugs.
With that in mind, the brands listed in this article are among the best in the market and should be able to provide you with an excellent set for your vehicle.