Most people don’t think twice about their spark plugs, yet these small parts play an incredibly important role in how your car functions. In fact, without properly working spark plugs, your car more than likely wouldn’t be able to run at all. In this blog, our auto repair experts will take a closer look at why your spark plugs are so important, including what they do and how to know when it may be time to replace them.
Your engine is a pretty remarkable machine, designed to turn an energy source (gasoline) into actual movement. But how does it do this? The answer is the principle known as internal combustion. To turn the fuel in your car from a source of potential energy into a source of kinetic energy, your engine needs to find a way to release it, and it does so through the combustion process.
The engine cycle is what makes this process happen. In your engine cycle, your valves fill your cylinder with a mixture of air and fuel, which are highly explosive when combined. As the piston in your engine moves upward, it compresses this mixture until it’s in an extremely small space, creating even more potential energy. At the peak of this compression, your engine ignites this mixture with a small spark, creating an explosion that forces the piston back downward, turning the crankshaft in your engine and creating the power which makes your car move forward.
Your spark plugs are what supply the spark that ignites the air/fuel mixture, creating the explosion which makes your engine produce power. These small but simple plugs create an arc of electricity across two leads that are not touching, but close enough together that electricity can jump the gap between them. Your spark plugs, along with the electrical and timing equipment which powers them, are part of what’s known as your ignition system.
Generally, your spark plugs are made from extremely durable material and are capable of withstanding millions and millions of explosions before wearing out or needing to be replaced. But it’s true that over time, the explosions and corrosion lead to smaller or weaker sparks, which leads to reduced efficiency in your engine, and could lead to other issues including misfiring, or failure to fire.
Most manufacturers these days will install “extended-life” spark plugs at the factory. They’re only marginally more expensive than a standard plug, and it sounds good to the consumer. Extended-life spark plugs are usually rated for a lifespan of around 100,000 miles. As these plugs approach the end of their life, the gap between the two leads begins to widen, which leads to reduced efficiency and the possibility of misfiring. If your plug corrodes to the point where it breaks, it could do serious damage to the interior of your engine cylinder, which leads to an extremely expensive repair to get it fixed.
Be sure to consult your vehicle’s owner’s manual to see how long of a lifespan your spark plugs are rated for. Never let your spark plugs go past their rated mileage.
When selecting new spark plugs, make sure you select ones that are right for your vehicle. Most auto parts shops will be able to help you do this, and you’ll have plenty of different models to choose from. Those which use precious metals like platinum or iridium will generally cost more than those which use common metals like copper, but they generally withstand wear far better.
A general rule of thumb is to select the same brand and model that the vehicle came with.
Resources:cbac.com