While you should buy spark plugs in matching sets for your vehicle, not all spark plugs are universal. Spark plugs come in different sizes with different gaps and are manufactured using a variety of metals. Finding the ones that you need can be difficult.
Performance Spark Plugs
At the simplest level, spark plugs can be split into two categories: standard and performance.
Manufacturers produce performance spark plugs for optimal combustion. The main difference between these and standard spark plugs is that the metal tab that the electrode arcs to during combustion is made from particularly durable metals, extending spark plug lifetime. There are single tab, dual tab and quad tab performance spark plug variations on the market.
Spark Plug Heat Rating
Heat rating refers to how quickly heat dissipates from spark plugs when they ignite. In a similar way to performance spark plugs, hot plugs maximise combustion by increasing temperature for ignition. Hot spark plugs are a popular choice for performance vehicles. Meanwhile, cold spark plugs are ideal for engines that already generate a lot of heat.
Spark Plug Electrode Materials
The metals used to manufacture spark plug electrodes offer individual benefits. For example, copper offers the best conductivity properties, though it isn't as durable as platinum and iridium.
Copper spark plugs: manufacturers use copper to produce spark plug cores with strong conductivity benefits. The 2.5 mm centre electrodes are typically produced using nickel alloys.
Double platinum spark plugs: the spark in double platinum plugs jumps from the centre electrode to the side electrode. The electrodes allow sparks to move in both directions without causing rapid electrode wear. This allows the spark plugs to retain their sharpness long-term.
Iridium spark plugs: these spark plugs are usually manufactured with 'fine wire' centres and 4 mm electrodes. The fine wire centres tend to make iridium spark plugs offer the best firing efficiency.
Replacing Your Spark Plugs
With varying spark plug gaps and lengths, it's important to buy the right ones when it's time to replace yours. Spark plugs that are too long can protrude into the cylinder and cause piston damage. Meanwhile, spark plugs that are too short will struggle to ignite and often cause engine misfiring.
Luckily, you can enter your number plate into our vehicle lookup tool. We'll tell you exactly which spark plugs are the right fit for your vehicle.
