The Best Spark Plugs in the World and Why

The Best Spark Plugs in the World and Why

rev up your engines, today I’m going to
talk about the best spark plugs for your car’s engine and why they are the best
ones, now over the past hundred something years spark plugs do one basic thing in
a gasoline engine, they fire the air and fuel mixture so there’s an explosion
that pushed the pistons down, now the early spark plugs hey they didn’t fire
all that great, the really early ones you could actually take them apart into
different pieces, clean them and fix them, put them back together and use them over, and
after that for decades and decades most spark plugs had copper electrodes in them,
copper is a good of conductor of electricity so they would conduct the
electricity that would make the spark that would fire the gasoline air mixture, but if you
know anything about copper hey it may conduct electricity quite well but it’s
extremely soft, so what happens is it would wear out in a reasonably short
period of time, back in a day when I was a young mechanic, hey you’d be lucky if
you got twenty thousand miles out of a set of spark plugs, sometimes we had to
change them even closer if it was an engine that was worn and burned some oil,
so they didn’t last all that long, then they went to platinum spark plug, because
platinum hey it’s much harder, it keeps its sharper edge long and where the
spark plugs fire you want a sharp edge for the spark to fire correctly, Platinum
spark plugs can easily last a hundred thousand miles and another
advantage of the Platinum spark plugs is they generally run a little bit hotter
than the copper plugs do, it’s running hotter they burn the deposits that get
on your spark plug off better so the spark plugs can last a lot longer, even
if your sparks firing right if it gets clogged up with unburned carbon parts it
won’t fire right, but then came Iridium spark plugs the top-line ones now,
iridium is six times harder than platinum, so it lasts even longer, plus it
has a 700 degree hotter melting point than the Platinum does, so they can last
an awful long time these Iridium spark plugs,
I personally have seen some Chevy v8 engines that had two hundred thousand miles on
them and the Iridium plugs had never been changed and it still ran fine, now
of course the iridium once cost more but hey the price keeps coming down, now you can
easily get them for seven or eight dollars a piece and there’s a big reason
that many engines now use iridium plugs from the factory, and that’s because
they’re making spark plugs harder and harder to get to, as an example this
Lexus behind me is a v6, the front three cylinders are real easy to get to,
they’re out in the open the front three simple to get to, but the back three are
under the intake manifold and you have to take the intake manifold plenum
completely off to get to those three smart plugs, it is a gigantic job, and
there’s many modern engine designs that are even worse than that,
some of them you practically have to pull the engine out of the car to change all the
spark plugs, so iridium makes sense if you can get two hundred thousand miles
out of a set of spark plugs hey most people are gonna be happy with that,
now the copper then the platinum then the Iridium, those are the three main
plugs that go into cars, but there are a bunch of these wild and crazy
manufacturers that design plugs that have four electrodes or are made all even
different materials and they claim they boost your horsepower and make you a
better gas mileage well, stay away from that stuff it’s just nonsense, now ages
and ages ago a spark plug design could have made a change like in the 60s where
you had points and condensers just mechanically opening and closing and
firing the spark plugs through the distributor, a lot of those systems
didn’t have all that much power and if you replace the stock spark plug in those
with one that fired better they would have actually run better, but it spent
decades and decades since theirs been points and condensers, all the systems are
electronically controlled now, the stock spark plug that comes with the car is
what’s designed for the car and will generally work best,
again in this 94 Celica hey it’s got electronic ignition in it, the stock
Nippon Denso was the best plug for it, it was designed by engineers it’s the right
fit and speaking of the right fit, let me tell you a horror story, years ago I had
a customer come over here with a 300 Z nissan sports car, and it
clacking like mad and I said, well when did this start and the guy said, well I
changed my spark plugs and right after I changed the sparks it just started
making all that noise, so I said okay let’s stop right there, I pulled out one
of the spark plugs, I looked at the spark plug and I could see the top of the
spark plug was hitting something it had metal shiny parts on it where it was
wearing, well nothing’s supposed to touch the top of the spark plug in the engine,
I went to my auto parts store and got a set of six spark plugs, and I measured
them against the spark plug that I’d taken out, well it turned out that the
spark plugs he installed were like this much higher instead of fitting flush like
this they stuck in the engine this much higher, and it was actually hitting the
top of the Pistons, it turns out he used a discount auto parts store and the
software that they had strangely enough was typed up in South Korea who knows
these days what kind of technology goes on, and one of those guys made a mistake
and they said that these long spark plugs belonged in his car that had
shorter spark plugs, they sold him the wrong ones, now he was extremely lucky
because he did it fast and brought it to me and I put in the right ones and after
about a day of driving the noise went away, so it didn’t really seem to have
damaged it in the long run even though that noise was pretty rattling to his
peace of mind when he started it up and heard it, so really you can’t beat the
stock spark plugs, always try to get the same exact spark plug the car came with,
and don’t trust anybody take one of your old ones out and when you take it out you
can either match the number this has a big number on it, or at least when they
sell it to you match it up to make sure it’s the same size and that’s exactly
the same length of threads as your old one, because you don’t want one that’s
too deep that’s gonna hit the pistons or one that’s too shallow and it won’t fire
the flame correctly, engineer spent years refining engine designs,
refining the spark plugs that go in them your going against all that knowledge if
you decide to swap out to a different spark plug, it has to be the right size
and it has to be the correct heat range for normal driving, but that said there
is one exception, you had a car that say came with a
Platinum sparkplug or a copper sparkplug you could upgrade to an Iridium spark
plug if an Iridium spark plug is made that will fit in there, you’re not gonna
get more horsepower, you’re not gonna get better gas mileage, but you’re gonna get
longer life, like in that Lexus it didn’t come with iridium plugs but I put them
in, because it was such a pain to take that manifold off I put in Iridium spark
plugs, now I have to admit the platinum spark plugs and I took out of it had
nothing wrong with them, I had to take off the valve cover gasket on that side
because even though it was a Lexus things wear out eventually and it was 16 years
old and this stupid little rubber gasket on the valve cover was leaking oil, I
figured as long as I’m taking that manifold off so I could change the valve
cover gasket I”m going to change the spark plugs too, if they make an Iridium spark
plug that will fit in your engine when you go to an auto parts store and they
look up and you match it with the old one that’s the same size, go right ahead
and put an Iridium version of the original spark plug, but don’t think that
there’s some magic spark plug out there that’s gonna make your car run better by
some crazy design that somebody thinks is going to work inside an engine better
than what the engineers designed it for and since this is mechanic Monday I’m
giving away a set of original equipment spark plugs, to have a chance to
win just place a clean non offensive comment on the youtube comments below
and the winner will be chosen randomly by a computer to get brand spankin new
original equipment spark plugs for their car’s engine, so if you never want to
miss another one of my new car repair videos, remember to ring that Bell!

About the Author: Michael Flood


  1. Great video Scotty! I used to work at autozone and half the time my coworkers had no clue about spark plugs so they would just recommend the most expensive ones and then customers come back pissed off finding out their cars run worse than their used set of plugs๐Ÿ˜…๐Ÿ˜…

  2. Why didnโ€™t you put this video out when I owned that #+!#$& Chevy Venture Van? I couldnโ€™t even find the spark plugs let alone change them! I know what kind of plugs that will be going into my Hemi when the day comes! Thank you!

  3. Good explanation, I thought my mechanic was crazy when he told me my iridium plugs didn't need to be replaced.

  4. Let me tell you one thing I was a mechanic for race cars built my own the best spark plug there is. IS Autolite. THE 2nd best spark plug is .A C . Those are the two best spark plugs in the world for cars.

  5. Why does he remind me of the actor Christopher Lloyd from the back to the ๐Ÿ”ฎ future movie…. ๐Ÿ˜Š

  6. Hey Scotty, or anyone else who would be able to answer this…My car is almost 10 years old and it runs fine. Even though my car only has 42K miles on it, should consider changing the plugs becuase they're nearly 10 years old?

  7. Hello I have a Ignition Coil question. Are aftermarket coils like a NKG brand as good as the stock ones?
    Thanks, love your videos

  8. Thanks so much for the video !!! Winner winner chicken dinner I have a 2005 PT Cruiser non turbo I need all the help I can get! Lol! Let me know when I win! Lol!

  9. ๐Ÿ“ฒ*00212645752301* *whatapps*๐Ÿ“ฒ
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    ุงู„ู€ู„ู€ูŠ ุนู€ู€ุงูŠู€ู€ุฒ ุงู„ู€ู€ุฏูƒู€ู€ุชู€ู€ูˆุฑ๐Ÿ‘จโ€โš•๏ธ ูŠู€ุชู€ูˆุงุตู€ู„ ู…ู€ุนู€ู‡ ุงู„ู€ูˆุงุชู€ุณู€ุงุจ *00212645752301*๐Ÿ“ฒ

  10. Can you convince the auto industry to take their educated engineers to a auto repair shop and have them change parts? They will soon realize that AutoCad software doesn't always relate to repairing a vehicle easily. Even though I know the manufacturer wants you to trade your car in when it exceeds certain mileage rather than fix it. Other than that your videos are educational and explain how to fix something or what not to buy in the future. thanks.

  11. Great segment, very infomative; I have a 2005 300C w/small HEMI. I need to change the plugs (16 of them) and I want the longest lasting I can get, iridium!
    Thanks, Scotty!

  12. Thanks for all your advice it is so helpful.I can't stop watching your vlogs .I'm from new Zealand do u need an apprentice lol you are my guru your knowledge is priceless thanks for sharing
    JD. Invercargill,new Zealand

  13. Scottie my teacher and a1 auto I learned more one guys so jelouses of him that's a mechanic he said scottie full of it .

  14. Hello scotty, I am using lexus rx300 MCU15 1998, is it ok to use RX 350 spark plugs as the engine is similar but different cc ???

  15. I put aftermarket heads and domed piston and the piston just tapped electrodes closed, I ended up having to use indexing shims.

  16. The best in the world, but follow what the manufacture put in…. whenever i hear the best in the world,,, oh well.

  17. Iโ€™m looking for a spark plug that functions as a gasoline direct cylinder fuel injector so I donโ€™t end up ruining a good set of heads!

  18. Back in The day, when i was a young mechanic…
    Scottyโ€™s grandchildren will be tired To listen to this, just To continue listening to that on youtube

  19. I know a guy that used to work at K-Mart automotive. This is what he told me so I'm taking him at his word. This was maybe back in the 1980's. They had a standard price for changing spark plugs in a car regardless of make and model.

    Apparently there was some car so poorly designed that in order to access the two spark plugs in the rear you actually had to at least partially remove the engine from the car. (This was the style of engine that was NOT turned sideways like most modern engines.)

    Anyhow, after that happened at that location and possibly at some other locations as well with that same exact kind of car, K-Mart had to stop charging a standard price for changing spark plugs.

  20. Scotty you talked about heat range and even said some get hotter than others, but didnโ€™t mention side gapping copper plugs. I am very disappointed because magically iridium and platinum are very low conductors of energy. I want the non magical ones because i care about performance. Because in fact magically theres as big difference performance wise as there is longevity wise. Why would I want one that lasts 200k miles but cause pre ignition? Why is it magically the side gapped copper ones all the sudden donโ€™t magically not conduct energy like platinums and iridium?


  21. Hey Mr. Scotty, im using copper spark plugs for my Lancer ES. So there is no other advantage of using platinum spark plugs other than the durability? (lets say for example, less carbon deposits from combustion?) Thanks! im a big fan.

  22. The bean counters are largely responsible for the difficulty encountered when making repairs on modern cars. Making cars difficult for the owner to repair makes work for the auto dealerships is another reason.

  23. After a day of driving the noise went away? Really? How much damage do you think the chunk of spark plug or piston that was banging around in there did before the noise went away?

  24. I really enjoy your show. I have a 1965 F100 6 cylinder which by the way I canโ€™t get it to run correctly. The engine valves overhead and it starts backfiring thru the carb. Got any suggestions.

  25. ๐Ÿ“ฒ*00212645752301* *whatapps*๐Ÿ“ฒ
    ุดู€ู€ุจู€ู€ุงุจ๐Ÿ™‹โ€โ™‚๏ธ ู„ุงุญู€ุธู€ุช ูƒู€ุซู€ูŠู€ุฑ ูƒู€ู€ูˆู…ู€ู€ู†ู€ู€ุชู€ู€ุงุช ุนู€ู€ู† ุชู€ูƒู€ุจู€ูŠู€ุฑ ุงู„ู€ู‚ู€ุถู€ูŠู€ุจ ูˆุถู€ู€ุนู€ู€ู ุงู„ุงู†ู€ุชู€ุตู€ุงุจ ูˆุณู€ุฑุนู€ุฉ ุงู„ู€ู‚ู€ุฐู
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  26. If we added Glow Plugs to gasoline engines alongside normal Spark Plugs, would they help out with cold starts when you're using harder to ignite fuels?

  27. The only problem I have seen with long life plugs is removing them after a lot of time and miles. Use a little anti-seize compound on the threads.

  28. very cool video. with older vehicles I've always told my customers about cheaper plugs. but with this info on newer rigs. I will make the iridium option available. thank you..

  29. Love your videos but was so disappointed when you said Nissan 300zx and used a picture of a Plymouth Laser lol. Thank you for the spark plug knowledge made my deciding platinum or iridium versus costย much easier.

  30. I used to sell auto parts and I remember our corporate (who you know always knows best) had us pushing these plugs named e3. I think we warrantied every e3 plug we sold. Absolute garbage. We had one guy who was traveling buy a set (and e3's were about $10 a plug) for his 1980s Ford Econoline van. He changed the plugs in the parking lot. Drove 12 miles to the next town TURN AROUND come back to the store and demand a refund. I warrantied the e3's handed him 8 Motorcraft plugs and about $25 in change.
    I was the assistant manager and I always told our younger guys, 99% of the time if it's Ford sell Motorcraft, GM sell AC Delco, Chrysler sell Champion, Honda or Toyota sell Denso and Nissan sell NGK. A lot of guys around seemed to really have good luck with NGKs in Nissans. I even ran NGK Iridium plugs in my 02 Sentra with a 5 speed (not the auto-tragic Nissan grind boxes of the era)

  31. Better Plugs Needed?

    Tailpipe dumps water or condensate out of the tail pipe….. Does that mean my gas is being wasted? I need a hotter spark…. Better plugs or a better coil or both? Maybe I need more Air? Air/Spark/Fuel…….. It has to be one of the 3, right?

  32. Hi Scotty would you please tell why resistances are used in spark plugs. Extra power is needed to overcome the resistances which is power loss.

  33. If you are running boosted car you want the copper bkr7e 4644 part number. If not boosted just get the platinum or iridium plugs . Do not put iridium or platinum on boosted car thatโ€™s running more psi than stock. You want 1 step colder than stock if you are boosted more psi for example 7psi stock to 10 or 15 psi. The more boost the colder the plugs anyways copper is cheap to replace and donโ€™t last long but itโ€™s better than buying a new engine and fairly cheap . Usually last 1000 miles or so if u run it hard . If your car is NOT boosted then run the iridium or platinum. Do the research

  34. I like the small solar cell behind Scotty in the car dashboard ๐Ÿ™‚ What's that for? Trickle charge the car battery or some gadget inside? Thx

  35. Scotty great,I am now observing that plugs are now getting bad because they are losing spark thru the glass insulated part of the plug.

  36. Although many mechanics "still" try to make the removal of an intake manifold a big pain in the butt, in reality, I would have to disagree with you on that point Scotty.
    Back in the day when Scotty was a young mechanic, the removal of the intake was a pain in getting to the bolts.

    Today's cars are made pretty easy in their removal with access to those bolts, designed into the engine. Rubber O-ring type of seals that work well.

  37. Scotty Kilmer … , my ex gf , poured a few quarts of bleach down where my oils goes … What can I do to fix it ! , I attempted to start my car ,it turns but it smells like bleach really bad , my mechanic is 17 miles away from my house , will I be safe to drive it ?? Or should I get it towed to him?

  38. My 2010 ram 1500 came with iridium plugs and never got changed until 185 000km. They worked fine but I changed them anyway. 16 plugs. Easy job but that's a lot of plugs. $$

  39. Good show. I go one step more. A/C for GM. Motorcraft for Ford. ND and NGK for japan made. Bosch for German. Champion for Chrysler and small engines.

  40. I bought a '99 Mercury Grand Marquis 4.6 V8 from from it's first owner with 102K original miles. (It now has 108K). I replaced the original Motorcraft Platinum plugs, with new NGK Iridium plugs: Amazing difference: Real Smooth Power! More than enough acceleration. Premium Gas required.

  41. Scotty always a great video. Surprised by how much you know….saw the insurance one and you were pretty spot on. Keep making these. They are great.

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