The Best Spark Plugs
Spark plugs are a frequent culprit when engine trouble arises. These simple devices are directly responsible for maintaining combustion in your motor and typically last less than thirty thousand miles before misfiring. That's why getting the right replacement is so crucial. With safety and reliability in mind, we decided to find the best of the best in the world of spark plugs. In our search, we asked three main questions: Is it made out of high-quality materials like iridium and copper? Does it have a reliable build free of misfires? Is the price fair? Our favorite was the option from ACDelco, which features a precise iridium electrode that runs as smooth as butter. However, if you have a little extra cash and want a spark plug worthy of a sports vehicle, we recommend the E3 Spark Plugs. They use a copper electrode for extreme precision and reliability at fast combustion rates. Clearly, there's a lot to consider. Read on for more of our in-depth reviews.
ACDelco 41-993 Iridium Spark Plug
A spark of genius
Replacing your spark plugs regularly is a sure-fire way to keep your engine running smoothly. If you run into troubles with your OEM variety, ACDelco’s spark plugs are a fantastic alternative that’s built to last. Constructed using an incredibly durable and heat-resistant iridium coating, this device can handle turbocharged engines and commuter vehicles alike. While we’re huge fans of the more precise electrode on display, it is extremely delicate.
Pros:
- We were thrilled to find spark plugs with a precise gap between the electrodes. In other words, you don’t have to (nor should you) fiddle with the gap to get a reliable arc every time.
- These have an interference-free suppressor, which means radio and other electromagnetic waves won’t cause misfires.
- The melting point is 700 degrees, so you don’t have to worry about these getting fried, even in hot and dry weather.
Cons:
- We wish the thread were a bit longer to offer some adjustability.
Champion Copper Plus 71 Spark Plug
Electrode-exploding deals
While many modern vehicles can accept spark plugs that use advanced materials, this isn’t the case with older vehicles and small engines. Thankfully, Champion’s Copper Plus 71 spark plug is designed to run smoothly across all engine types. Copper is a highly conductive metal that performs at a much cooler temperature than rare metal counterparts, a major plus for performance vehicles. This plug will certainly outperform the pack as far as misfire prevention, although the inferior exterior coating means replacements will be more frequent.
Pros:
- Champion spark plugs are wickedly versatile, so they’re a top pick for a wide range of small-engine vehicles, like lawnmowers, tractors, and generators.
- Unlike fragile iridium electrodes, the copper electrode on this one is durable and high-performance. That means that if you need to gap it, it can handle all the fiddling without taking any damage.
Cons:
- For commuter vehicles, we recommend something with a longer lifespan.
E3 E336 Power Sports Spark Plug
Profound performance plug
If you need to push as much fuel into your engine block as possible for high-stakes competition, check out the power sports spark plug from E3. Unlike most ignition devices that share a similar schematic, the E336 relies on an open-end design known as DiamondFIRE. This configuration projects electric current deeper into your vehicle’s combustion chamber, resulting in a more thorough burn per cycle. Not only does this enable more power output during races, but it leaves less unspent carbon in your system, a huge factor that reduces greenhouse gas exhaust.
Pros:
- These spark plugs are infused with yttrium, which means they have a significantly higher melting point and durability compared to standard options.
- These spark plugs may provide a noticeable increase in torque, especially if they’re replacing old low-performance spark plugs.
Cons:
- The higher quality comes at a higher price.
NGK 6509 Iridium Spark Plugs
Reinforcement for your ride
Drivers looking to fully upgrade their engine or stock their garage for future repairs will find value and consistency with NDK’s iridium spark plug pack. While spark plugs may seem fairly consistent as far as general build, NGK directs its focus towards overall system stability. As a result, these plugs boast a superior gasket that excels at leakage prevention and high-quality threading for easy removal once they’ve worn out. Best of all, NGK’s ultra-fine tips use less voltage per spark than most competitors, providing relief for your electrical system and vehicle as a whole.
Pros:
- If you’re looking for the best bang for your buck, go with these. They offer fantastic quality at a bargain price, so it’s the ideal option for those looking to replace all the spark plugs in their 6-cylinder vehicle.
- These can even reduce the ignition time for your vehicle since the pre-gapped iridium electrodes fire precisely every time.
Cons:
- The packaging could use more padding to protect the spark plugs during transit.
Frequently Asked Questions
How does a spark plug work?
Spark plugs can be thought of as the match that ignites the gasoline in your vehicle’s combustion chamber. To start, smart plugs produce a level of voltage determined by the gap between their electrode points. When you turn on your vehicle, the key’s ignition switch tells your battery to send a current through a resistor and into the ignition coil, where low voltage turns into high voltage. At this point, the current travels to the distributor, a metal enclosure that contains the central shaft, rotor arm, and distributor cap. After traveling through the distributor cap’s electrode, the current finally passes through the moving rotor to power each cylinder’s individual spark plug.
What are the most common signs of a faulty spark plug?
Because engines depend on consistent electrical current to operate, defective spark plugs can wreak havoc on your ride. The main reason why spark plugs lose their efficacy is that they accumulate fuel residue and heat damage over time. Both of these scenarios weaken the spark-inducing tips of the component over time, leading to misfires first and total inactivity later. Malfunctions like this mean that the engine’s cylinders are wasting uncombusted fuel, which can result in symptoms like rough idling and slow acceleration. Additionally, this uncombusted fuel will lead to corrosion inside the combustion chamber, increased greenhouse gas emission, and lower overall gas mileage.
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