Best Spark Plugs

Best Spark Plugs

Don’t let their small size fool you—spark plugs emit an electrical spark across a tiny gap to ignite the combustion required to start your vehicle. By setting your motor’s pistons in motion, your ride can roar to life, stay running, and deliver a smooth burn of the compressed air-fuel mixture.

Spark plugs also make a significant difference in how smoothly your vehicle operates. That’s why selecting the correct spark plugs or replacing your old spark plugs is a vital part of maintaining your car.

We reviewed dozens of spark plugs to identify the best of the best, based on Amazon reviews, how well they performed in performance tests, cost, and other considerations. We narrowed our search down to 5 of the top-rated spark plugs motorheads can purchase to ensure a smooth-running ride.

Why Worry About Spark Plugs?

Having high-quality spark plugs in your car ensures that your engine remains a top performer and efficient. The best spark plugs take the already high-performance engine to the next level. Without proper plugs, your car experiences are misfiring. Besides, you will notice your car becoming less fuel-efficient and problems with exhaust emissions.

Avoid these problems and potentially save your engine from enduring the associated damage by finding the best spark plugs in the market. The spark you need may be different depending on the type of vehicle and engine you have. This is why we have outlined a buying guide to ease your search process.

5 Best Spark Plugs of 2021:

1. Denso (3297) SK20R11 Iridium

Denso (3297) SK20R11 Iridium

The iridium used to make Denso spark plugs is six times harder and eight times more durable than platinum spark plugs & because of the durability, there is less electrode wear.

Another important note to remember is Denso partners with other manufacturers to supply OEM (original equipment manufacturer) parts for your car.

Denso 3297 spark plugs increase your car’s performance and acceleration. Because of the durability of Denso spark plugs they can be used in high performance cars such as off-road vehicles.

This product also stabilizes combustion while your vehicle is idling. The stabilization ensures smooth idling when your car is stationary. According to professional mechanics and positive reviews, the Denso spark plugs should last for at least 100 000 miles.

You’ll find that when you install Denso spark plugs your car will start up more easily and your engine will run a lot smoother. Denso spark plugs are also known to improve your vehicle’s miles per gallon (MPG) stats.

  • Improves your car’s performance
  • Decreases the risk of engine fouling
  • Only fits some car applications

2. NGK 6619 Iridium IX Spark Plug

NGK 6619 Iridium IX Spark Plug

The NGK 6619 Iridium IX Spark Plugs snags the top pick in our spark plug comparison because they offer the best mix of high-performance, fuel efficiency, durability, and dependability. Featuring an iridium construction, these high-quality spark plugs provide a longer lifespan than copper and platinum spark plugs.

Their ultra-fine electrode wire promises superior fuel efficiency as well as silky-smooth engine idle and response. You can also expect a healthy boost in power and torque thanks to the optimal air-fuel mixture that these iridium spark plugs generate. They receive top marks for durability with such impressive features as metal plating to resist corrosion and seizing, as well as a long insulator nose to prevent fouling.

We were hard pressed to come up with any cons for these spark plugs, but if we had to ding them for something, it would be their rather expensive price per spark plug. This higher price may seem like a big ask for more frugal motorists, but the exquisite quality and peerless performance that the NGK 6619 spark plugs deliver make them well worth their cost.

  • Durable
  • Made with premium materials
  • Only need to be changed after 100 000 miles
  • Expensive

3. Bosch 4417 Platinum+4 FGR7DQP

Bosch 4417 Platinum+4 FGR7DQP

The Bosch 4417 Platinum+4 FGR7DQP Spark Plug is our runner up choice for the best spark plug, thanks to its unique plug tip design which has been completely re-worked from the ground up. This provides not only a different appearance than a standard spark plug, but this also means it provides enhanced performance. The plug-and-play installation makes it a breeze for swapping out your old spark plugs when it’s time for a change.

Those who purchased and reviewed this spark plug appreciated that these plugs ran longer than less expensive ones, and were impressed with the torque, power, and overall performance they provided. A premium manufacturer of electrical goods, Bosch is a name that many consumers associate with quality products and customer service.

At a cost of around $18, it certainly doesn’t come cheap, but the quality craftsmanship associated with the brand, as well as the ease of setup and use more than justifies that price. It has a rating of 4.6 on Amazon with more than 200 people reviewing it, which we think goes a long way in convincing gear heads that this is another spark plug that’s worth the investment.

  • Utilizes 4 yttrium-enhanced electrodes
  • Low maintenance design
  • Increased longevity
  • Doesn’t fit all car applications

4. Autolite 104 Copper Resistor

Autolite 104 Copper Resistor

Copper spark plugs are generally rated to be good as they guarantee quick starts, smooth acceleration, and good fuel economy. The Autolite 104 Copper Resistor Spark Plug is the industry standard. The plug comes with all you need for a well-running engine, initiated by spark plug ignition.

The full platinum tip ascertains that there is no gap for erosion. This indirectly translates to a longer plug life. It is also Yttrium enhanced with a high nickel alloy as the side electrode. The alloy maintains a precise gap, further increasing the plug’s life.

Necked down center electrode of the Autolite 104 Copper Resistor Spark Plug fires quickly and cleaner. It also requires less voltage for easier starts, improved fuel economy, and quicker acceleration. For extended durability, the plug features a platinum alloy pad on the ground electrode. Finally, yet importantly, the nickel-plated steel shell if corrosion resistant ascertaining longer life.

  • Full copper core for better performance
  • One-piece terminal adds strength
  • Multi-rib insulator reduces flashing-over danger
  • Good plug for the price
  • Copper doesn’t last long

5. NGK V-Power Spark Plug

NGK V-Power Spark Plug

With over 8 decades of experience, NGK is one of the biggest names in spark plugs. Years of experience creating specialized sensors, connectors and other car engine components have helped earn NGK a reputation as a trusted brand noted for quality and consistency.

The company’s V-Power spark plugs feature a unique electrode design with a built-in notch, which creates a unique spark shape that helps improve mileage and performance while contributing to cleaner, longer-lasting electrode surfaces.

The V-Power plugs also feature NGK’s Trivalent Metal Plating technology to help resist corrosion and provide superior anti-seizing characteristics—making them a great pick for the do-it-yourselfer. Affordable pricing and a variety of fitments for many cars, trucks, motorcycles and power equipment applications means it’s easy to find the right set for your needs.

Notably, NGK’s V-Power spark plugs offer greater ignitability from less system voltage—meaning more power and efficiency, and reduced strain on other ignition system components. A long list of stellar owner reviews suggests that these plugs are the way to go, and well worth their slight pricing premium for confidence, proper fitment, and overall performance and satisfaction.

  • Ideal for the DIY enthusiast
  • Long life
  • Improved performance from V-Power electrode
  • Not ideal for all applications

Best Spark Plugs Buying Guide & FAQs

There is our list of the best park plugs out on the market today. As we mentioned up top, these deceptively simple products are in fact very important to the smooth running of your engine, and when they start to fail can reduce fuel efficiency by up to 30%.

So choosing the correct plugs is very important. To chose the right ones you need to understand how they work, how to work on them and how to spot the signs of the spark plug is perfect for your needs.

How Spark Plugs Work

Well this seems as good a place as any to start – how do Spark Plugs work? Well sir, you just plug them in and they spark. Simple. Ok, they are a little more complex.

A spark plug is first and foremost an electrical device. It plugs into the cylinder head of a typical engine (*). The cylinder head is flooded with a mixture of air and fuel (gasoline) that the spark plug ignites. This tiny explosion (and that is really what it is!) drives a piston that is attached to a crankshaft that transfers the energy (via a couple more connections) to the wheels of your car, propelling the vehicle.

Types of Spark Plugs

  • Iridium – Top-rated spark plugs on the market have an iridium construction. They give you even better performance, gas mileage, dependability, and longevity than double-platinum plugs.
  • Platinum – Platinum plugs provide improved performance and fuel efficiency compared to copper plugs, but for a considerably lower price than iridium ones. Much like iridium plugs, platinum products operate at a lower temperature than copper options.
  • Double-platinum – They deliver even more efficiency, performance, and longevity than single-plated platinum plugs. Plus, double-platinum plugs are still typically cheaper than iridium plugs. For an affordable upgrade from single platinum, look for products that have platinum in both the cap and electrode.
  • Copper – Copper spark plugs are the most basic and affordable form of the plug that you can get. They’re the most common plug type on the market but have recently been replaced by iridium and platinum devices due to their superior efficiency, performance, and lifespan.



In typical driving circumstances, you should use the spark plugs specified by your vehicle’s manufacturer. A hot plug may be a good option if your spark plugs are fouled from carbon deposits, your engine has a rich air-fuel ratio or burns oil, or if you do a lot of local low-speed driving. If your engine is pinging, has a lean air-fuel ratio, or if you do a lot of high-speed driving, consider a cold plug.


This depends on the quality of spark plugs you have in your car. Top-quality spark plugs will last longer than lower-quality plugs. Most mechanics recommend you change your copper core spark plugs every 30,000 miles or every 50,000 miles for iridium core spark plugs. This interval may be shorter if your engine isn’t in top condition, so it’s vital to inspect your spark plugs for premature wear and change them accordingly.


You may notice the following symptoms if your spark plugs need to be replaced: hesitation or backfiring during acceleration, decreased acceleration, rough idle, spark plug wires charred on the end that goes onto the plugs, a significant drop in fuel economy, and difficulties starting your engine. If your ride doesn’t run as well as it usually does, and you suspect it’s attributed to bad spark plugs, inspect the plugs yourself or have a mechanic do it.


Yes, you can clean your spark plugs, but it’s generally not recommended. When you clean a spark plug using a wire brush or sturdy knife to scrape off the deposits, it can dull it and drastically lower its efficiency. If you insist on cleaning your spark plugs, use a spray-on plug cleaner specifically engineered for this vital component.