Originally Posted by StrangeRanger

With or without the coil, it's the tuneup and the optimized timing that adds the performance. The hotter coil does nothing to improve volumetric efficiency so it does not increase the amount of fuel/air mixture the engine burns. You might argue that the hotter coil causes more complete combustion but I seriously doubt that it does. The emissions requirements for unburned HC have already insured that combustion on late model engines is as complete as it can be.