No such thing.. That's something you figure out when your tuning your engine. The plug rating will change based on boost, fuel, compression, etc.. For instance a standard plug works for street on many, but if your at teh track you running a cold race plug and changing them more often. The multi electrode plugs usually dont need the gap adjusted. Cheers. __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black |