What a spark plug is for?

There are two systems in a vehicle that need to be glued with a help of electricity- an ignition system and the combustion chamber. This is where a spark plug is needed. A spark plug essentially transports electric current between the ignition and the combustion. Having spark plugs that function properly is the absolute key for the engine to run smoothly. Best performance spark plugs would make your engine smoothly revving for the long stretch of time without needing to check it.

Product comparison table: best spark plugs


Denso (4504) PK20TT Platinum TT Spark Plug, (Pack of 1)

Denso (4504) PK20TT

NGK 5464 BKR5EIX-11 Iridium IX Spark Plug, Pack of 4

NGK 5464 BKR5EIX-11

ACDelco 41-110 Professional Iridium Spark Plug (Pack of 1)

ACDelco 41-110

Champion RC12YC (71G)

Motorcraft SP-515 Spark Plug, Pack of 1

Motorcraft SP-515

Bosch 9652 Double

NGK (7092) BKR6EGP

Material Platinum Iridium Iridium Copper Platinum Double Iridium  Platinum 
Weight 0.32 ounces 1.6 ounces 2.08 ounces 1.6 ounces 1.6 ounces

0.8 ounces

1.92 ounces
Dimensions 1 x 1 x 3.6 inches   0.3 x 0.4 x 1.3 inches 6.4 x 3.4 x 0.9 inches 3.7 x 0.8 x 0.5 inches 2.7 x 2.1 x 3.8 inches 4.1 x 3.5 x 1.1 inches 48.2 x 41.5 x 10.9 inches
Year 2007 2005 2014 2010 2015 2009 2010


The types of spark plugs

The different kinds of spark plugs available today are classified as per the type of metal their main parts are made of. These types are:

1. Copper / nickel / normal spark plugs

These spark plugs utilize coating made of nickel alloy, while the inner part of it is made of copper.They are usually the cheapest, but have a shorter life than other types have.

2. Platinum spark plugs

These spark plugs utilize platinum center electrode.They have longer life than normal, nickel spark plugs, as platinum succumbs to erosion way less than nickel does.

3. Double platinum spark plugs

“Double platinum” spark plugs have platinum-made plating on both the center electrode as well as the ground electrode.These plugs prove to be of even longer lifespan that single-platinum spark plugs described above.

4. Iridium spark plugs

Iridium spark plugs are often considered finest of all.They provide the longest lifespan across all types. They also ensure the smoothest run of an engine.

5. Silver spark plugs

When it comes to the conducting properties, silver spark plugs are hard to beat. They are usually the most expensive of all.


How many spark plugs are installed in your engine?

Depending on the type of an engine, the amount of spark plugs varies.

How many spark plugs in a v4 engine?

V4 has four cylinders, and features, consequently, four spark plugs. In racing cars, they usually install twin-spark engines, making the total of spark plugs 8.

How many spark plugs in a v6 engine?

But for most vehicles equipped with a V6 under the hood, there are six (6) spark plugs. The exception is if your vehicle carries with a twin-spark engine, which would carry the doubled amount of spark plugs, meaning 12 pieces.

How many spark plugs in a V8 engine?

V8 engines feature 8 spark plugs. If an engine is double-cylinder, you would need 16 spark plugs.

Spark Plugs: top 5 curious facts

We selected top-5 curious facts about spark plugs that may come off as improbable. The misunderstanding stems from many reviewers as well as regular car owners not understanding what do spark plugs do and how exactly their functioning is affecting the engine performance.

1.Fine wired plugs are “hotter” in turbo/super-charged vehicles?

Actually, sometimes the opposite is true. Take Dodge Hellcat of 2018, which reaches 707 horsepower with 6.2 liter engine. This engine carries an iridium plug.

2. A spark plug with a copper as a core is less efficient in burning carbon-deposits that fine-wired ones. As a fine-wired plug is hotter than a regular one, it will burn off deposits easier.

3. A dual-purpose vehicle, for example, street-and-drag, requires different heat range as opposed to “regular” s.

4. treet-drive one. For the latter, you might want to add extended nose plug.

5. The more horsepower you squeeze, the more it is dependent on pre-ignintion. Before settling with a permanent spark plug for the high-horsepower vehicle, it is a good strategy to test it with the coldest plug with a short-ground electrode.

6. An extra gap in a power-adder-app can be a root of misfiring. A lot of naturally-aspirated motоrs would benefit from a bit wider-than-normal gap of 0.045-0.050 inches.

Comparing spark plugs in our selection by material/weight/the price per unit.

Denso (4504) PK20TT Platinum TT Spark Plug, (Pack of 1)

Denso (4504) PK20TT Platinum TT Spark Plug

These easy-to-install Densо spark plugs are very reliable. There is nothing extraordinary about them, though. The center electrode is platinum while the ground one is titanium. A plug features alumina-powder insulator ensuring durability, stress-resistance and good conductivity. This is the lowest how much spark plugs cost.

On the downside, there is still the risk of misfiring.

NGK 5464 BKR5EIX-11 Iridium IX Spark Plug, Pack of 4

NGK 5464 BKR5EIX-11 Iridium IX Spark Plug

These iridium spаrk plugs are made of alloy of top-quality iridium. They make possible proper combustion. They are also very reliable, as traditionally the melting point is very high with iridium.

Another advantage of these is installed trivalent metal-plating, which helps to block corrosion as well as to prevent any possible leakage.

ACDelco 41-110 Professional Iridium Spark Plug (Pack of 1)

ACDelco 41-110 Professional Iridium Spark Plug

Made of iridium, these plugs ensure proper idle-stability and overall smooth performance of your motor. The cold-starting is dependable while acceleration benefits from the use of the plug. The plugs make carbon burn quickly as the deposits are accumulated on the very end of the plug.

The gapping on these plugs needs to be performed very precisely, as improper gapping might damage your motor.

Champion RC12YC (71G) Copper Plus Small Engine Replacement Spark Plug

These Champion spark plugs are characterized by the ceramic insulator with higher density and hardness. This combination allows for the greater accuracy as far as greater heat ranges. The copper-cоre of the central electrode is provided for longevity and performance. These are one of the best spark plugs for gas mileage.

The downside of these Champion spark plugs is that they may not last too long as compared to iridium/platinum ones, and the replacement might be needed after a while. They also require more voltage than the fine-metalled plugs.

Motorcraft SP-515 Spark Plug, Pack of 1

Motorcraft SP-515 Spark Plug

These spark plugs are manufactured and designed to be installed only in Fords.

The advantages of using these spаrks include their highly calibrated built, so there is no need to gap them. The overall install process has proved to be very simple.

The downside of these Motocraft spark plugs is that even though these plugs are advertised as Ford-friendly sparks, they may not fit for your particular make & model of a Ford vehicle. Make sure to check your model before buying these white spark plugs.

Bosch 9652 Double Iridium Spark Plug – 4X Longer Service Life

These plugs feature a dоuble-iridium firing-pin. The upside of using these fine plugs is that they carry almost zero probability of misfiring owing that to a sharp-pointed pin that allows firing even at low voltage. Iridium plugs have the best corrosion resistance there with the highest melting point. In our opinion, these spark plugs provide better conductivity than Bosch platinum spark plugs. Overall, these Bosch spark plugs are the longest-lasting plugs in our selection. These are best spark plugs for horsepower, overcoming even Al Deco spark plugs in this respect.

NGK (7092) BKR6EGP G-Power Spark Plug

The flagman of the sparks niche, NGK, comes forward with another G-power platinum-alloy plugs. NGK spark plugs are designed to make your engine functioning efficiently fuel-wise and busting your power performance. In their class, they show overall decent performance.

These plugs feature customized gap, that should and would stay put for the whole life of the spark.

Why and when to change spark plugs on your vehicle

How often do I change a plug?

Most vehicles manufacturers suggest replacing old plugs every 30 thousand miles. It should be noted, that the timeframe may vary depending on the type of stark plugs that would affect its longevity.

That is, copper plugs have the shortest lifetime of all, while finer spark plugs, such as iridium, may serve you 4 times as long. There is no universal timeframe as far as changing spark plugs goes. Always refer your manual or get in touch with the manufacturer of your car to make sure how often to change spark plugs.

How to check spark plugs?

The symptoms of bad spark plugs include either of those or any combination of those:

  • Rattling or knocking noises your motor makes;
  • The rough idle;
  • Troubles with starting a vehicle caused by misfires;
  • Sluggish performance;
  • Above-average waste of fuel. This is not a tell-tale sign of a plug being worn-out, but you need to inspect your spark plugs and make sure a motor gets the right heat at the right time;
  • Crackings in the upper or lower part of the insulator of the plug;
  • Chipped/broken insulator tips;
  • Damaged plug boots.

If you want to change spark plugs yourself, follow these steps to determine when to change spark plugs.

How to change spark plugs?

  1. Cool the engine down.
  2. Take the boot of a plug and carefully rotate it 90 degrees-counter-clockwise; then pull out the boot and the cable.
  3. Clean the accumulated dust/dirt with a brush or an air-blaster.
  4. Ease each plug one/ two turns.
  5. Remove spark plugs and sort them out just so you know later to what cylinder each plug belongs.
  6. Take dialectic grease and apply it to the boot area.
  7. Follow the gap guide to make sure you install new plugs accordingly. Remember, that gaps vary from engine to engine and you should follow the guidelines to determine how tight should spark plugs be.
  8. Follow the manual for glowing plugs to the proper torque.

The best spark plug of 2018: our recommendation

Among the spark plugs we reviewed and tested, we recommend:

Bosch 9652 Double Iridium Spark Plug – 4X Longer Service Life (Pack of 1).

At around $4.29 per item, these double-iridium plugs allow for the smoothest run among its class with the lowest probability of misfiring. Bosch always manufacturers top rated spark plugs and never fails to deliver the product without any serious downsides.

Follow our future spark plugs reviews.

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