I work at NASA and used my car to test a new spark plug that is being developed here. It was supposed to provide better power, mileage and produce less ozone depleting exhaust. As with most beta tests, none of this happened and I want to go back to my originals, but they threw them out. I was told I should have asked to keep them. I am on my own to replace them and I have no idea what was in the car originally. Should I get an after market? If so, what kind? I have also read that they are a pain to replace. Any help would be greatly appreciated.