At the top of the list, we have the NGK Spark Plugs. With iridium as its core material, this spark plug pack can operate at a much wider heat range as compared to ordinary spark plugs made out of platinum or copper. These spark plugs make combustion gas leakages nearly impossible with an overly protected triple gasket sealing process that’s patented by the manufacturer. Available in a pack of six, these spark plugs rank amongst some of the highest reviewed spark plugs on the online marketplace across a variety of platforms.
Combining a top material composition of iridium with world famous Japanese engineering, this spark plug set is easily the best overall option on our list.
The Autolite Spark Plugs are the only other option that has an iridium core. These plugs feature a nickel top to take the smallest possible hit on performance while still being a highly affordable product in its category. Engineered to last over 100,000 miles, this pack of four spark plugs is one of the most durable options available today.
This impressive longevity comes from over a century’s worth of research, development, and experience as the brand has been around since 1911. They’ve mastered the art of automotive parts, with their spark plugs offering top-notch levels of fuel efficiency, ignitability consistency, and enhanced durability in their flagship iridium construction. The secret behind their impressively high fuel efficiency involves a fine-wire iridium tip design, as well as the platinum protection on the ground wire which is standard in all of their iridium spark plugs.
At number three, we have the ACDelco Spark Plugs. With a platinum core, these plugs offer the perfect blend of performance, durability, and value. While they feature only a single-plated platinum build, the top is made out of titanium, which is a relatively high-end material as compared to other spark plugs in this price range.
According to the brand, you can install this spark plug into your car and expect your engine to start faster, accelerate quicker, and experience better fuel economy. But these flashy promises don’t matter if the plug doesn’t last long. The manufacturer has strengthened these spark plugs with an alumina electrical insulator for optimal thermal conductivity, which results in sharper performance and improved durability in the long run.
Next up, we’ve got the E3 Spark Plug. At under $10, this spark plug is one of the cheapest spark plugs you can find on the online marketplace. A major reason behind that is that it’s a copper model which is quickly becoming an obsolete type of spark plug. But this spark plug might be the only one that fits your needs if you’ve got an older vehicle with a distributor in its engine.
The top is made out of alloy steel and it’s designed to fit universally on cars that are compatible with copper plugs. The manufacturer’s patented DiamondFire technology gives this spark plug excellent heat transfer capabilities while also being able to withstand rough engine vibration. Another patented edge-to-edge design technology offers quick and effortless engine start-ups by concentrating spark energy, making it a practical choice for distributor-based ignition systems.
Our last pick is the Denso Spark Plug. Thanks to its miraculously low price, while still featuring a platinum core, this spark plug is a must-have for those looking for an affordable option. At under $5, it’s the highest value you can expect to get out of your money within the automotive parts industry. Even with its low price, you’ll still get a decent build quality with twin-tip technology featuring a titanium ground electrode and a platinum core electrode at the center.
Even though this spark plug is cheap, it still has a platinum core which means you can expect faster starts, improved fuel efficiency, and better acceleration response with these plugs in your engine. It’s the ideal choice for those who like keeping some spare parts lying around the garage in case of an emergency.
So far, we’ve featured an overview of the description, pros, and cons of some of the highest-quality spark plugs that are available on today’s market. But you still need to narrow it down to just one, so here’s a detailed buying guide to help you navigate the market like a true motorhead.
Below, we’ve included everything you need to know.
Not all spark plugs are built the same. They can be classified into five categories, each of them better suited for a certain demographic of drivers.
Let’s start with the most premium choice out there — iridium spark plugs! The highest-end plugs feature an iridium construction as the reliability, performance, fuel average, and lifespan they offer are unmatched. But the material quality and the innovative technology that’s integrated into these plugs drive their price up, which can be a limiting factor for those who are looking for an affordable option. These plugs are generally only used in performance cars.
Next, we’ve got platinum spark plugs. These plugs are a high value for the money, giving you considerably higher performance, gas mileage, and longevity that’s second only to iridium plugs. They can last about twice as long as their copper counterparts, making them a popular choice in city cars and some sports cars.
These used to constitute the biggest portion of the spark plug market as they’re the most affordable and the most basic. In recent years, iridium and platinum spark plugs have overtaken copper spark plugs as a more popular option due to better efficiency, performance, and durability. While many older engines prefer copper spark plugs for optimal performance, most modern motor engines are not compatible with them.
The double platinum spark plug is a reinforced version of the regular platinum spark plug. They use platinum material in both cap and electrode, providing even better efficiency, performance, and durability than single-plated ones. They’re a significant upgrade in performance from regular platinum plugs while still being much cheaper than iridium ones, which makes them a sweet spot for those looking for an affordable option for their performance cars.
Following the same theme as above, double iridium is an enhanced version of the regular iridium spark plugs. Using iridium material in both the electrode and cap, these spark plugs are the best ones you can find on the market today. They’re good enough to supply you with tons of power in any driving condition, including back-to-back high-speed laps on a performance racetrack. On average, these last four times longer than an old-school copper plug, which goes to show how far modern motor technology has come!
Since the classification of spark plug types is wholly based on their material composition, you can tell that material is an important factor that plays a key role in their performance and reliability. It’s important to consider which type and material fit your particular car.
If you have a classic vehicle that still has a low-voltage, distributor-based ignition, copper spark plugs might be your only choice. For modern engines that don’t have distributors in them, you’re better off with iridium or platinum plugs.
Platinum offers a perfect blend of performance and economy, paired with a long lifespan. But iridium provides even higher performance and longevity, but at a considerable price premium. Your decision mainly comes down to your budget constraints as you can’t go wrong with either of them.
A great option that splits the difference between the two is a double-platinum spark plug which is ideal for most people.
Size plays a key role in determining whether or not a spark plug is right for your car. Size refers to the nut size. The measurements that are ideal for your engine vary depending on the make, model, and year of your vehicle.
A reliable way to determine what size of replacement spark plug you need is to closely inspect the one that you’ve already got installed. If you were the first owner and haven’t changed the spark plug before, then the one you have would be company-fitted as an OEM part. See what size nut it has and follow suit.
Spark plugs that conduct more heat out of the tip are better at bringing down and maintaining a low temperature. The industry calls these plugs cold plugs. Plugs that insulate heat well generally have a higher operating temperature due to the conserved heat, which specifies them as hot plugs.
Generally, your spark plug should be well-balanced on that spectrum, though manufacturers tend to err on the side of coldness because a plug that runs too hot can severely damage your engine, whereas one that runs too cold will simply stop working sooner.
The heat range of a spark plug is denoted by an ascending number for hotter plugs, though some brands follow the same pattern of ascending numbers for colder ones so you’ll have to pay close attention to their product pages to know exactly what you’re paying for.
Lastly, spark plugs are engineered with calculated spark gaps that are adjustable using a gapper tool. If a single plug is designed to be compatible with several different engines, it’ll need a different gap to fit each one. For cars, plugs range between 0.024 and 0.071 inches. Before you spend your money on new spark plugs, make sure that it falls into the specified range that fits your car’s engine.
On average, spark plugs should last for 30,000 to 90,000 miles depending on the quality, material, type, and brand of plugs you use. Some iridium ones can last beyond the 100,000 mile mark without even the slightest drop in performance.
The biggest sign of a faulty spark plug is that your vehicle has trouble starting up or vibrates with rattling noises when you’re idling at a traffic light. If your engine performs smoothly and steadily, the plugs are performing as they should.
A spark plug that starts to malfunction leads to a number of concerning problems, including hard starts, misfires, worse fuel efficiency, and poor acceleration.
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