Solid core wires don't produce a hotter spark. They do allow much higher current flow in the plug wires, which does nothing to ignite the fuel better, but it does drastically reduce the life of distributor caps and rotors due to the intensity of the arc that jumps around inside the cap. Solid core wires also produce a huge amount of radio frequency interference with electronic devices, particularly AM and CB radios and VHF television signals. FM and UHF isn't affected as badly, so unless your neighbor is into CB, he's not likely to take a Louisville Slugger to your headlights for messing up his conversations. I'm not sure what RF interference does for cell phone signals and other personal electronics.
Jerry
