Can Performance Spark Plugs Add To Your Car's Horsepower? Here's What You Should Know

There are plenty of affordable ways to boost your car's performance. Some people prefer installing performance exhausts and remapping the engine, while others lean more towards cold air intakes or investing in a set of performance tires. However, none of these mods can be fully utilized if a car's ignition system isn't able to provide the necessary spark to fire reliably in every cylinder, cycle after cycle. This is why we turn to performance spark plugs. So, can they add to your car's horsepower?

It depends on the circumstances, but yes, performance spark plugs can give your car more horsepower by restoring the performance and smoothness that has been lost due to old spark plugs. On the other hand, if the spark plugs are fresh and the engine is well-maintained, switching to performance spark plugs alone is not going to give you more than 1% to 2% more power. Here's what you should know about performance spark plugs and whether they actually make a difference in power.

A performance spark plug is designed with features and materials that make it more conductive, efficient, durable, and consistent in operation. Materials such as iridium or platinum enable electrode designs that require less voltage to spark and thus aid in efficiency. Moreover, due to a more consistent sparking, performance plugs improve acceleration and torque, and that is why upgrading your spark plugs is a great way to make your car run more smoothly.

On average, iridium spark plugs can last as long as 100,000 miles. This is a lot longer compared to traditional copper plugs, which are usually able to last between 20,000 and 30,000 miles. Lastly, performance spark plugs also benefit from finer plug tips to promote quicker sparking. This combination of durability, consistency, and longevity makes performance spark plugs a worthwhile upgrade, even though the expected power gains might not be all that dramatic on their own.

To get the most out of performance spark plugs, they should be paired with a healthy ignition system. The gapping on the plugs should also be set to your engine's specifications, as even the smallest of deviations can alter combustion stability and performance. More specifically, a study published in the 2013 AVTECH Conference by M. A. Faghih concluded that a 0.75-millimeter plug gap offered maximum power, while smaller (0.5-millimeter) and larger (1.0-millimeter) gaps reduced it.

With a melting point of around 2,450 degrees Celsius, iridium-tipped spark plugs are better for turbocharged, high-RPM performance engines since these can endure a lot more heat. A higher heat range allows for more consistent spark under heavy engine loads. It's also important to note that performance spark plugs shouldn't be viewed as standalone performance upgrades. They should be a part of a more holistic approach where performance plugs are paired with other engine mods to make more horsepower reliably, safely, and in harmony with the rest of the car.