The engine in your GM car or truck runs on the energy released by its internal combustion. Spark plugs are what deliver the electrical current that ignites your fuel. They help your vehicle both start and continually create the power it runs on. Without a reliable set of genuine GM spark plugs, its ignition system wouldn't work at all. Explaining just how spark plugs work first requires explaining how some other engine parts work. First, your engine valves let a combo of air and fuel into its cylinders. Second, engine pistons compress the blend, making more of its energy available. Finally, your spark plugs ignite the mix, forcing the piston back down and turning your crankshaft. Eventually, ignition systems weaken. Sparks can even get smaller because of increased distance between plug leads or wear and corrosion. The result is engine inefficiency, misfires, and even outright firing failure. Even worse, bad spark plugs can break, leading to massive engine cylinder damage and expensive engine repairs. Luckily, it's easy to tell when to change spark plugs. Because GM spark plugs come straight from the factory made of high-strength materials, they can withstand ignitions in the millions before replacement is required. Many are even designed for an extended life of around 100,000 miles. Review your owner's manual for info on spark plug lifespan and be sure you aren't using any beyond their mileage limitations. The question of what you should get is also an easy one. The best spark plugs for your GM car, truck, or SUV are OEM. You can order them online in just a few clicks here at our auto parts counter. Browse our selection, buy today, and save on your next project!