Types of spark plugs

The main types of spark plugs are copper/nickel, iridium, single platinum, double platinum, and silver.

Copper Spark Plugs

The center electrode of this type of spark plug is a copper core coated with a nickel alloy. It has the largest diameter of all the other spark plugs, so it needs more voltage to generate a spark.

Nickel alloy is a material that is soft and not very durable, so spark plugs will need to be replaced more frequently than other types. Some cars are designed to use copper spark plugs despite their shorter lifespan.

In some of these cases, installing more expensive spark plugs may be a waste of money. Check the owner’s manual for manufacturer recommendations.

Pros

• Inexpensive
• Appropriate for older vehicles built before 1980
• Performs well under high-compression or turbocharged conditions

Cons

• Shorter lifespan
• Requires more voltage

Iridium Spark Plugs

Iridium spark plugs last the longest since iridium is harder and more durable than platinum. These spark plugs have a small center electrode which requires less voltage to generate a spark. These advantages are reflected in the higher price tag.

Many car manufacturers are now using iridium spark plugs in their vehicles, so it’s important to stick with iridium when replacing the plugs rather than downgrading to platinum or copper/nickel. That could adversely affect the performance of the vehicle.

Pros

• Leads to more complete combustion
• Long lifespan
• Requires less voltage

Cons

• Expensive

Single Platinum Spark Plugs

A single platinum spark plug is similar to a copper/nickel spark plug, except that its center electrode has a platinum disc welded to the tip instead of an only nickel alloy. The platinum metal lasts longer than nickel alloy before being worn away.

These plugs also generate more heat, which reduces carbon buildup. This is the recommended material for new cars with a coil-on-plug ignition system.

Pros

• Long lifespan (up to 100,000 miles)
• Reduces carbon buildup

Cons

• Expensive

Double Platinum Spark Plugs

Double platinum spark plugs have a platinum coating on both the center and ground electrodes. This is more efficient and longer-lasting which makes these plugs a great choice for a wasted spark ignition system, which exerts more wear on both electrodes than other ignition systems.

In a wasted spark ignition system, each ignition coil fires two spark plugs at once, one in the compression stroke’s cylinder and the other in the exhaust stroke’s cylinder.

The spark for the latter gets wasted because the air-fuel mixture was already burnt on the previous stroke. This ignition system is an improvement over distributor ignition systems because it isn’t affected as much by rain or debris.

Pros

• Recommended for wasted spark ignition systems
• Reliable

Cons

• Expensive

Silver Spark Plugs

These are less common than others and feature silver-coated electrode tips. These do not last as long as iridium or platinum spark plugs as the metal is less durable. They are most often used in older European performance cars and motorcycles.

Pros

• Best thermal conductivity

Cons

• Decreased longevity

Please consult your owner’s manual for the spark plug that best suits your vehicle or contact your nearest e-CAR workshop for advice, sales, and fitment.