Delphi GN10633 Pencil Coil Delphi uses winding process techniques to control the length of wire between adjacent windings That's important since more length means greater voltage differences and can create more pressure that could break down the insulation and wire coating Delphi ignition coils are engineered to OE specifications Built with the benefit of more than 100 years of Delphi's OE heritage our coils are designed and endurance tested to resist the common stresses that cause failure We back our ignition coil design with proven materials such as high quality wires and wire coating that resists the cracks pin holes and imperfections that most often lead to failure issues