Copper spark plugs are the most used spark plugs even today. They may not be the best performance spark plugs anymore. But they sure are economical.
So, what are copper spark plugs, and what are their benefits?
Spark plugs with copper electrodes are called copper spark plugs. Nickel is usually added to the copper to form an alloy that is more rust-proof.
Copper spark plugs are readily available and are of low cost. As a result, they provide decent performance for a cheap price.
This isn’t to say copper spark plugs do not have drawbacks.
For more details on them, let’s dig deeper.
What are copper spark plugs?
Spark plugs with copper electrodes are called copper spark plugs. As simple as that. Nickel is usually added to the copper to form an alloy that is more rust-proof.
As for what are spark plugs, you can read our post here on what spark plug function and use.
Copper spark plugs are still in fact the widely used spark plug type in automobiles.
The reason why copper spark plugs were so popular boils down to two main reasons. First, copper is cheap. Second, copper is an easily available material for manufacturers.
The low cost and ease of sourcing made copper a go-to material for spark plugs among the available options that could conduct heat and electricity.
But there are downsides as well.
Copper has a melting temperature of 1085 celsius. While this is a reasonably high melting point, as a material used for spark plug center electrodes which generate 20,000-volt electric spark and can get super hot, you expect a far higher temperature withstanding capabilities.
In addition, copper oxidizes fast to form a rust layer.
This is not at all desirable in a spark plug. To overcome this hurdle, Nickel is usually added to form an alloy. Other metal pieces are also used in the spark plug to overcome this low melting temperature. They are used to distribute the heat.
The resulting copper and nickel alloy are more rust-proof. But on the flip side, the material becomes softer and wears out fast.
Pros and cons of copper spark plugs
We have discussed this in the previous section. Still, let’s do a recap.
Copper spark plugs are low-cost and widely used. This has to do with their ease of sourcing for the spark plug manufacturers. In short, copper spark plugs are economical.
But there are problems that come with these low-cost spark plugs.
First, copper spark plugs cannot operate at high temperatures. Copper has a low melting point and if the spark plug gets too hot, it is a concern.
Second, nickel is usually added to copper to form an alloy. While this makes the spark plug rust-proof, the flip side is it becomes soft and wears out fast.
Third and last, copper spark plugs do not last long. The lifespan of copper spark plugs is around 20,000 miles, far lower than its alternatives – platinum (single and double) and iridium spark plugs.
To summarize:
Pros
- low cost and economic spark plugs
- Easy to source and manufacture
Cons
- Cannot withstand extremely high temperatures
- Wears out fast
- Has a short life span and needs to be replaced early
Price
A typical copper spark plug will cost you around $2.5.
Even accounting for the various versions and manufacturers of different copper spark plugs, you would still get a copper spark plug in the range of $2 to $5.
I mean, if you ever see a copper spark plug costing $10, just skip it. You can buy an iridium spark plug (the costliest of the lot) for that price.
If you are buying a set of spark plugs, then a set of 4 or 6 spark plugs should be in the price range of $10 to $20. The price depends on the spark plug type and how many plugs are there in a set (usually it is 4 or 6).
How long do copper spark plugs last?
Copper spark plugs usually last around 10,000 to 20,000 miles.
The best practice is to replace the spark plug for every 10,000 miles of distance traveled. In addition, the spark plugs need to be checked every 4000 to 5000 miles traveled.
As for why the spark plugs need to be replaced, spark plugs over time will stop performing well.
This can be because of worn-out electrodes, deposit formation, or insulator damage. But mostly, deposit formation.
The carbon deposits start accumulating on the electrodes which over time will mask the spark plug preventing it from generating sparks.
A masked spark plug with excessive carbon deposits will not ignite the fuel properly in each combustion cycle. As a result, there will be an uneven acceleration in the motorcycle along with the wastage of fuel.
That’s why you need to check and replace the spark plugs periodically. As for how to do it, check out these steps to replace a spark plug.
Are copper spark plugs better?
Copper spark plugs are better in terms of cost only. They are cheap and widely used. But that’s it.
Copper spark plugs are not at all the best when it comes to performance, operating temperature, or longevity.
Iridium spark plugs are the best performance spark plugs out there. They can withstand high temperatures and have a higher lifespan as well.
But the downside is iridium spark plugs are costly. 3x costlier than copper spark plugs.
Platinum spark plugs are somewhere in middle between these two spark plug types. Both in terms of performance as well as cost.
Which spark plug is the best?
Depends on what parameters you look for in a spark plug.
Copper spark plugs are cheap and the best spark plugs. Not the best out there in the market. But for the money, they work decently well.
Purely in terms of performance, Iridium spark plugs are the best type of spark plugs. They deliver superior performance and have a higher life span.
However, iridium spark plugs are costly. Not many are eager to go for them.
That brings us to the point. Often the best spark plugs for your motorcycle engine is the one recommended by the OEM.
So, always check for the spark plug recommended in the owner’s manual. If your vehicle is recommended to have iridium spark plugs, you just can’t downgrade to a copper or platinum spark plug.
On the other hand, if the manual recommends a copper spark plug, it probably is best to go for copper spark plugs rather than upgrading to a platinum or an iridium one.
