There only $5.99 each so it wasnt like they were expensive. I run Platium splitfires in my truck and no difference felt. I do understand the ignition and sparkplugs. I have figured that on the splitfires it was kinda like indexing the plugs, the split electrode has a wider spark which exposes it to the intake charge better. The E3 I dont know but I did see dyno info on them and they gained about five HP which is not alot but I wanted to change my plugs and thought I would give them a try. I have a plain chrome box and mopar dist. that I have recurved. Im an electronic technician by trade. Bill