HEETACHE DUAL COIL GLOW PLUGS
Dual Coil Glow plugs, as their name implies, have two heating elements instead of just one. The addition of an extra coil allows the glow plug to have a "self-regulating" feature. In the past, glow plug design was a balancing act. If resistance was low, the plug would get very hot quickly, but would burn out. If resistance was high, the glow plug would heat up slowly, and not get very hot, but last virtually forever. Dual coil designs have what is called a "positive temperature coefficient" – the hotter the glow plug gets, the higher its resistance goes. This allows the glow plug to get very hot quickly for faster starts, but gives extended life at the same time.
