Are there different types of spark plugs?
Your engine requires at least one spark plug per cylinder to ignite the air/fuel mixture and get the engine running. But not all spark plugs are the same. There are several different types on the market and you need to make sure you are getting the right type. Also, your vehicle may have more than one spark plug per cylinder (some high performance engines have two).
Spark plug types
PerformanceA: One of the first types of spark plugs you'll find is performance - they come in a variety of styles, although the only thing that really differs is the shape, configuration, and placement of the metal tab at the bottom. This is what the arc electrode is to. You'll find single-tab, two-tab, and four-tab configurations available, each claiming better performance than the others. However, there is conflicting evidence as to whether these types of plugs actually offer great advantages over a single tongue design.
Heat ratingA: Another consideration when buying spark plugs is the glow rating given by the manufacturer. It is essentially a designation for how quickly heat is dissipated from the tip of the spark plug after an arc has formed. If you need higher performance, you will need higher heat output. In normal driving, this is not so important.
Electrode MaterialA: You have undoubtedly seen many different electrode materials on the market. They range from copper to iridium to platinum (and double platinum, for that matter). Different materials do not affect performance. They are designed to make candles last longer. Copper wears the fastest, but provides the best conductivity. Platinum can last a long time, as does iridium, but neither offers better performance than regular spark plugs, except for the high cost of exotic metals.
The best type of spark plug for your car is most likely the same as the manufacturer's. If you're not sure what it is, check your owner's manual or talk to a trusted mechanic. However, if you're modifying your engine for performance, you'll probably want to look for a high performance spark plug that will provide better combustion.
