E3 Spark Plugs E3.20 Performance Spark Plug used primarily in 4-cycle overhead valve engines.; The result of independent research and testing suggests that using E3 car spark plugs in your vehicle can increase horsepower when compared to more conventional spark plugs. Our patented Edge-to-Edge electrode outperformed other plug designs including some premium spark plugs offered by the major manufacturers. Plus E3 automotive spark plugs will continue to offer that like-new performance over the long haul and help to extend the life of your car s engine. Regardless of the brand model or style of the vehicle that you drive our plugs are designed to deliver an optimum spark to your car s new or aging engine. Developed in conjunction with researchers from leading universities we designed our car spark plug to create a faster flame front so the unburned air-fuel mixtures that would normally pass into the engine s exhaust system experience a more complete burn. Isn t it about time to put the DiamondFire power of our car spark plugs to work in your car SUV minivan truck motorcycle snowmobile or ATV? Sold Individually. ;