Types of Spark plugs | Which is Best?

The spark plug is a key component of the engine system, playing a major role in fuel economy, clean and efficient combustion, and the reliable operation of engines and catalytic converters. A typical spark plug can generate up to 100 sparks per second, amounting to over 20 million sparks throughout its lifespan.

A Spark plug consists of a metal threaded shell, a ceramic insulator, and a central electrode. The connector or terminal at the top of a spark plug is where the ignition wire attaches, the connector connects to the copper core of the center electrode. Next is the hex head. This is where you put your socket, which fits for tightening and loosening the plug in its hole in the engine.

Now below that's a gasket that compresses tightly against the cylinder head. The ground electrode is made of metal, with options ranging from stainless steel to titanium. It can come in several shapes as well, from notched or Y-shaped electrodes to triple electrodes.

The spark plug requires 15 to 20 thousand volts to generate a spark, whereas the car battery provides only around 12v so to create a higher voltage an ignition coil is used. It transforms the battery's low energy into the thousands of volts needed to create an electric spark in the spark plugs, to ignite the fuel. Inside every ignition coil, there are three main components an iron core a primary winding, and a secondary winding.

---- Time Stamp ---
00:00 - Introduction to Spark Plug
02:02 - Construction
03:34 - How Spark Plug Sparks?
05:10 - Gap of Spark Plug
06:42 - Cold vs Hot Plug
07:36 - History of Spark Plug
11:36 - Copper Spark Plug
12:51 - Platinum Spark Plug
14:21 - Iridiuim Spark Plug
15:19 - Multi-Electrode Spark Plug

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Disclaimer: This video is for educational purposes only. We are not in the auto repair business nor publish automotive service manuals. This video is not reviewed or authorized by any vehicle manufacturer. This video is intended only as general guidance. Every system is slightly different, so refer to the owner’s manual of your vehicle for any specific information about your model. Remember that only proper service and repair procedures will ensure your car's safe and reliable operation.

Copyright Disclaimer: Copyright Disclaimer Under section 107 of the Copyright Act 1976, allowance is made for “fair use” for purposes such as criticism, comment, news reporting, teaching, scholarship, education, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational, or personal use tips the balance in favor of fair use.

[TheShornak]

I worked in a Honda dealer in the service department in the early to mid 90's. At that time those multi electrode spark plugs were becoming popular. I remember a customer coming in with his brand new civic. This was a 93 I believe. He complained of a rough idle and wanted it fixed under warranty. But what the technician found was the customer had replaced the spark plugs to those dual electrode plugs. All we did was put the factory plug back in sure enough the engine ran smooth as it should.

[chrissmith]

As the video points out, the bigger the gap in the plug, the more voltage is needed to jump it... This means that leaving the spark plugs in too long can cause the electrical insulation in the coil to break down and cause the coil to fail. When the power to the 'primary coil' is interrupted the magnetic energy in the iron core collapses and is transferred to the 'secondary coil' and the voltage in the secondary coil will keep rising until it is relieved by the spark happening, if the gap is too large the voltage can reach extreme levels. The use of Iridium and platinum is to massively reduce the 'spark erosion' that causes gap wear, so this allows plug gap to stay in specification for a lot longer. Many coil failures are caused by the plug gap being allowed to get too large

[synthwave]

You are 100% correct - new cars are not very DIY friendly - the modern car has become a complex piece of machinery. At 13:26 this is a glow plug. For those that don't know - Diesel cars do NOT have any spark plugs.

[CedroCron]

The information about Hot and Cold plugs were good... I do find that colder plugs in a hotter plug specified engine such as those that have fuel/air mixtures on the leaner side such as Chrysler Lean Burn tuning, seem to give a smoother running engine and don't foul so long as you don't go too much colder. Ford also has a new sparkplug in the later Ecoboost engines that have a copper crush washer and when tightened to the specified torque, they will all be properly indexed the same way due to the threads in the cylinder head and threads on the plugs being in certain alignments causing the plug to always align in a specified manner to encourage a more complete burn.

[happycat]

I have had NGK iridium plugs in my 2002 Rav4 and have had zero problems over the last 7 years whatsoever! If you have a new car the NGK iridium are highly recommended as these spark plugs will last at least 15 ~ 20 years!

When I removed the NGK plugs after 7 years the plugs were a little brown in colour but looked almost close to new!

[kelvinnwosa]

Has anyone noticed that modern equipment have become less simpler but more complex. There are creating an ecosystem where you keep needing their services and keep paying them rather than doing it yourself. The concept is profit driven. Once you make a simple machine very complex the more money you can make from sales and repairs.

[BaronMoulton]

A good teacher is like a candle it consumes itself to light the way for others.

[danielgaskell]

In many published dynamometer runs since the early 2000’s both car and bike magazines have shown that multiple ground-electrode plugs cause engines to lose 2-3 h.p. at the medium to high rev ranges. Additionally, the 60K to 80K volt ignition coils on modern engines allow the plugs to maintain efficiency to at least 60K miles and in some cases 100K miles.

[steveperry]

a friend and coworker of mine was a real car guy and would drag race his street 95 camaro. one of the things he did for a bit of a boost was to index the plugs with shim washers to have the electrode pointed right at the intake valve. he also reversed flowed the heads and altered the chip for the throttle body and the thing was really fast and quick.

[Thor-bjpn]

Absolutely the best spark plug video ever. Perfection! This video should be the model for all vehicle components. Do it!

[mrvang]

The Stock spark plug that came with the vehicle is way better than those aftermarket spark plug that failed prematurely. Best bang for the buck would be the original parts.

[bruceheadley]

I've only seen multi-anode sparkplugs used in aircraft engines, and they run dual sparkplugs & magnetos.

For cars & motorcycles, I've had good luck with ND Hot-U and iridium split anode sparkplugs .. get slightly better fuel economy, engine feels a bit peppier and cold starts seem quicker

[theokool]

Excellent explanation of the topic, clear narration and superb graphics to illustrate the processes, thank you 🙏 subscribed because it made me want to listen and watch 👌😊👍

[jeyapaljayaraman]

Accurate and awesome tutorial significantly covering all areas on spark plug subject. Thanks a lot for the easy, understandable professional coaching ❤

[suhayl]

beautiful video; thank you. I once had a 2005 Durango with 5.7 hemi; took it to dealership to service the A/C. they found out that I had 100k kilometers and still running the original spark plugs. there was no problem at all. so changing spark plugs every 20, 000 miles? not so sure..

[frequentlycynical]

Once upon a time, pre mandated unleaded fuel, only Amaco premium gas was lead free with an octane rating of over 100. With leaded gas, 10, 000 miles was about the limit before needing replacement...along with the points and setting of point "dwell" and ignition timing.

Spark plugs are cheaper now than they ever have been, not even counting inflation. Iridium plugs are da bomb. I've got over 200K on a set and they are just fine. Check once in a while, never a reason to replace, especially since a few require some effort to R & R.

[Ekimsrevo]

Also it is very important to properly torque spark plugs 45 years as a tech their are a lot of cars that it's not easy to get the plugs out. Also be careful buying plugs online their are a lot of counterfeit parts sold

[jamesbosworth]

Multi-electode plugs were a thing in the early teens, (20th century), until everyone realized that more fire for the firing surface gave better results than more surfaces for the fire.

[deefective]

In case you didn't know unless you are an aircraft mechanic, the spark plugs with 4 electrodes is called and igniter. They are used in aircraft engines because of the obvious redundancy. Just in case.

[pauljanssen]

It all depends on the shape of your combustion chamber including the type of piston. Absolutely do not never use
E-V spark plugs. And not all brands work the same on certain engines.