Contour Enthusiasts Group Archives Forums Modifications Duratec Performance NGK Iridium plugs

Rules for Spark Plugs 1) You dont get any more power by changing the plugs,can loose power with the wrong plug but recovering lost power isn't a 'gain. 2) The make of plug also has no bearing on power, gap and grade have to be correct ,the engine does not know which brand of plug it has! 3)Multiple ground plugs(+4 etc) offer a longer service life...nothing more 4)Precious metal plugs offer increased efficiency because electrodes can be thinner and gaps larger which will reduce misfires & improve starting.They do not give more power 5) Cannot improve cylinder burn with a diffrient plug design, once the mixture starts to burn the spark is long gone 6)Color of plugs tells little,main point on plug selection should be heat range...