Iridium spark plugs - advantages and disadvantages

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Spark plugs are a fairly important element in a car engine. A lot depends on their operation - stable operation, starting (both cold and hot), fuel consumption and even power. Therefore, manufacturers are constantly working on this element, improving it. One of these “evolutionary leaps” is the iridium (some call it platinum) spark plug. However, if you read reviews on the Internet, opinions categorically differ! Some write that this is a “miracle of miracles” with all the advantages that I listed above (it also has a huge service life). Others write that there are no changes at all, and the engine works even worse! WHERE IS THE TRUTH? I have experience with such elements, and therefore there is something to tell and show, let's think about the pros and cons (as usual there will be a video version at the end) ...

At the very beginning I would like to talk a little about iridium and platinum. There are rumors that they are one and the same. This is not entirely true, of course, iridium is a platinum group metal, but it is a transition element, and the production methods are slightly different (we’ll talk about this below). But platinum options (for example BOSCH Platinum) have a truly platinum, but very thin central electrode, which is locked (as if poured) into a dense ceramic insulator.

Although in fairness it is worth noting that some manufacturers call iridium versions platinum, or cover the contact points with platinum using a similar technology to iridium (this is not the point now). I will have a separate article about this, so be sure to follow the blog.

Denso IW20, Denso W20 EPR

It’s not easy to pay about 3,000 rubles for a set of candles, knowing that your neighbor paid less than a hundred for similar ones. All the advantages of an expensive purchase are only in the future: the long mileage promised by advertising, some percentage of daily fuel savings, ease of starting... In addition, there is no need for frequent replacement: on a modern engine this is a labor-intensive and expensive procedure.

We decided to evaluate two polar designs from one reputable company in order to compare not the technology of different manufacturers, but the idea itself embodied in metal, all other things being equal. The choice fell on Denso.

Iridium IW20 are the obvious leaders in miniaturization of the central electrode: only 0.4 mm. It is the thin electrode that promotes better self-cleaning and, accordingly, extends the service life. They were accompanied by the usual W20 EPR-U. The initial difference in cost is approximately fivefold.

Service life of iridium spark plugs

We have already talked about different types of spark plugs on our website Vodi.su. One of the most reliable are spark plugs, the central electrode of which is made not of ordinary heat-resistant alloys based on nickel or steel, but of iridium and platinum. It is iridium spark plugs that belong to the highest price segment, but at the same time they have a lot of advantages:

high strength, stability in operation;
The melting point of iridium is very high, so it is used in gas-powered cars;
Trivalent nickel plating is used to protect against corrosion;
high spark efficiency - a simple calculation shows that only by replacing spark plugs with iridium spark plugs can fuel savings of 5-7 percent be achieved;
Less voltage is required to produce a spark due to the fact that the tip is thin and the potential difference is concentrated in a small area.

Other advantages emerge from these points. So, due to the fact that iridium spark plugs require less voltage, a stable spark is achieved even when starting the engine and at idle. Thanks to this fact, engine performance also increases by an average of 8 percent.

It is clear that to implement such technologies in life, manufacturers had to significantly modernize their equipment. For example, the performance of spark plugs is largely ensured by the use of high-precision laser welding, with which the side electrodes are welded. Also, the thickness of the electrode is only 0.4 millimeters, that is, thinner than wire (the thickness of the electrode of a standard candle is 0.8 mm). With such a small diameter, the resistance in the electrode can be practically neglected.

If you install such spark plugs on your car, you will see significant improvements:

the engine will run smoothly, even at idle;
its productivity will increase;
fuel consumption will decrease;
The spark plugs will not need to be changed for a very long time.

The only drawback is the high cost. Depending on the type, prices for one candle produced by Denso in Moscow will be 500-900 rubles. Whereas standard nickel candles from the same company cost 90-150 rubles.

Service life of iridium spark plugs

First of all, it is worth saying that there is a service life recommended by the manufacturer. But many car enthusiasts do not listen to this advice and continue to use candles.

The service life of an iridium spark plug is on average 3-4 times longer than a standard nickel spark plug. So, if the manufacturer recommends changing the latter every 30-45 thousand kilometers, then iridium ones can last from 60 to 160 thousand km. And this is according to the manufacturer's recommendations.

If you want to use them to the last, then their service life will be up to 200 thousand kilometers. It is advisable, of course, not to exceed the recommended period of use. In addition, it is very important to install the candles correctly, tightening them to a certain point, otherwise all their advantages will be lost and they will quickly become unusable.

Factors that reduce service life:

low-quality fuel - due to the formation of soot, spark efficiency decreases;
pollution - dust from the street, various particles from fuel or motor oil also settle on the spark plugs;
Frequent starting of the engine - it is during startup that the heaviest load is placed on the ignition system;
various internal problems with the engine.

Thus, if you want to spend money on good spark plugs at one time and not return to this issue, at least until your car reaches 100-160 thousand kilometers on the speedometer, then we recommend paying attention to Iridium Denso spark plugs or an improved version - Iridium Denso TT (Twin Tip), Iridium Denso SIP (super ignition), Iridium Denso Tough. NGK products have also proven themselves to be quite good - one such candle will cost you about 450-900 rubles.

( 5 ratings, average: 5.00 out of 5)

An increase in CH toxicity indicates disturbances in the combustion process.

An increase in CH toxicity indicates disturbances in the combustion process.
An increase in CH toxicity indicates disturbances in the combustion process.

According to the resource, the count in engine hours is 360:240. In all operational parameters - from consumption to toxicity levels - iridium is also confidently ahead.

Hence the conclusion: if you have an expensive modern car and you put a lot of miles on it, it makes sense to spend money on iridium. But if the car is so-so, and only travels no more than 5 thousand a year, you are unlikely to recoup the investment. Such is the deceit of expensive things...

Mikhail Kolodochkin, and associate professor of the department of internal combustion engines of the St. Petersburg Polytechnic University, Ph.D. Alexander Shabanov

Choosing spark plugs: iridium or regular?

Iridium metal

I’ll insert a little information for general development, you need to understand what kind of element this is

Iridium is an element with atomic number 77 (in the D.I. Mendeleev system). A very hard, refractory, silvery-white transition metal of the platinum group. It has high density, high corrosion resistance, resistance to acids and alkalis (even at temperatures of 2000 °C). It is found extremely rarely in terrestrial rocks, therefore it is quite expensive and valuable. Melting point - 2466°C.

As you can see, it is an almost ideal metal for use in a combustion chamber, if not for its price.

Does it make sense to use “long-lasting” candles if you can buy ordinary ones?

Choosing spark plugs: iridium or regular?

Problems with conventional spark plugs

Now I will not talk in detail about the operation of these elements. But we need to understand that the main load is carried by two electrodes - central and side (a spark passes between them). It is they that wear out over time and the element itself needs to be replaced

Typically, the side electrode is made of steel, which is alloyed with manganese or nickel.
The central electrode is made of iron-nickel alloys with the addition of copper and chromium.

Not only is a strictly defined gap set from the factory, but a certain resistance is also selected (about them below) so that the ignition coil can “break through” it and give the desired strong spark.

Over time, usually 50-80,000 km, the electrodes become smaller in size, the gap grows and the coil cannot effectively produce a spark (it turns out weak), the car does not pull, and fuel consumption may also increase.

This happens because the central and side electrodes simply lose some part of the metal; it simply burns out from constant discharges.

If such a spark plug is not replaced in time, or the gap is not adjusted correctly, the ignition coil may fail (because it needs to work harder to “break through” the greater height between the electrodes)

That is why spark plugs are replaced at 3-4 maintenance intervals, that is, 45 - 60,000 km.

Iridium or conventional – which is better?

Now we come to the most interesting part, but what is actually better than the iridium options - the usual ones?

There are few differences here, but as many manufacturers assure, they are significant:

Sometimes the central and side electrodes are doped (as it becomes clear) with iridium. Now there are different application options:

Two small spots on the electrodes (which are made using conventional technology)

Alloying of the central part with iridium, and a special U-shaped groove is made on the side, but it is not alloyed

Two electrodes, opposite each other. One is platinum, the other is iridium.

As we know, this noble metal has very good characteristics of melting, wear resistance, corrosion and electric current transmission.

Also, the central part is usually narrowed, making it literally like a needle. If you compare the central electrode of a regular spark plug, it is approximately 2.4 - 2.8 mm, but the iridium version is only 0.5 - 0.8 mm.

This way we get a concentrated and very strong spark. And the coating or soldering of this noble metal makes the working surface virtually wear-free. That is, the gap between the electrodes lasts a VERY long time, many say about 100 - 150,000 km. BUT nothing lasts forever, as soon as the coating of this platinum group metal is destroyed, the working surfaces of the electrodes are literally immediately destroyed

I know, many can - but why can’t ordinary candles have the same thin central part? Everything is simple here - the combination of iron-nickel with copper and chromium cannot also perfectly withstand electrical discharges, temperature, corrosion like an opponent made of noble metal, it will simply wear out and collapse faster (literally in 10-15,000 km), thereby increasing the gap and worsening characteristics. That is why it is made much thicker so that it can withstand the effects of an aggressive environment.

Cost of iridium spark plugs

In the modern world, the cost of a particular part is an important factor in making a purchasing decision. Despite their considerable cost, iridium spark plugs are still cheaper than platinum ones. This is explained by the fact that this metal is not in great demand on the market. Because the production of candles requires little of it. So, the tip alloy is half made of rhodium.

About 20% of all mined iridium is used for spark plugs for vehicles. In the case of platinum, this figure is much lower, since most of this metal is used in jewelry and catalytic converters. In addition, very little iridium is used for candles: only for the production of tips and grounding electrodes. However, due to their rarity, the cost of sets of iridium spark plugs is still quite high. The price of one candle can be from 600 to 800 rubles , and if we consider a set, from 2500 to 2800 rubles , while a set of simple ones costs around three hundred rubles.

MY REVIEW

Well, and finally, I would like to talk about my experience of using it (leave a review, so to speak). I bought iridium from FORD FUSION, because it seemed to me that my original spark plugs had already died and required replacement (and it was fashionable to try it then). I paid about 2,000 rubles for the set back then, when my original spark plugs (bought from a dealer) cost about 700 rubles, that is, almost three times more expensive. I took DENSO brands, selected them according to the catalog as usual.

I didn’t feel any global changes, the car became a little more cheerful, but only because the standard spark plugs already had burnt electrodes and their gap increased. Consumption did not drop, super power of 10% did not appear either. Winter starts were excellent for me and with the original FORD spark plugs.

I drove about 60,000 km on them, then I sold the car with them. They did not cause any trouble, the gap remained as it was, there was not even a hint of the electrodes burning. I usually changed the standard spark plugs at 50,000 km, they also did not cause problems, but with such mileage the central part began to wear out a little.

WHAT IS MY PERSONAL CONCLUSION. If you have the money, you can overpay for the iridium options, they really work well and for a long time, and it seemed to me that winter starts are, if only a little, better. HOWEVER - THEY ARE EXPENSIVE. With this money (for me personally) it was possible to buy almost three sets of ordinary spark plugs, and actually drive even more on them (together). I DIDN’T FEEL ANY increase in power or reduction in fuel consumption, BY 10% AT ALL!

Now let's watch the video version of the article.

Now let's vote on what you think is better

This is where I end, I think my material was useful to you, SINCERELY YOUR AUTOBLOGGER.

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Clearance and Resistance

Each manufacturer selects candles from certain manufacturers for itself. Here there is not only the required gap, but also resistance.

A gap of about 0.8 - 1 mm is considered normal; the resistance of the spark plug is usually not indicated on the body, but in sellers' catalogs you can select it specifically for your engine.

It is worth noting that if you take an element of incorrect clearance and resistance, then on the contrary, you can worsen the performance of your car ! After all, the spark plug is matched to the ignition coil of your exact make and model. THIS NEEDS TO BE UNDERSTANDED.

I installed the iridium version, but the car began to work worse

This also happens often - but why? The answer is simple - you chose the wrong option for your car (usually you buy what a friend recommended, it works so well for him). As I already wrote above, all cars have certain ignition coils, different compression ratios, etc.

Therefore, the spark plug must correspond not only in terms of overall dimensions (size, height and thread), but also in terms of clearance and resistance

A gap difference of 0.2 mm, which you may not visually see, can worsen the performance of your internal combustion engine. The same thing happens with the resistance of the spark plug, it must match your electrical circuit. If you take it with increased resistance, then again the coils will not work correctly (give a weaker spark), and they may even fail.

That's why NORMAL SELLERS have special catalogs (or programs) using which they select iridium or regular spark plugs for you.