I know both plugs are medium plugs but I think I heard someone say that one is a little bit hotter then the other, do you know which of the 2 is hotter? I know this is gonna sound crazy but with the werks plug I can not get a steady idle in either engine. I can put the nova plug in and have no problems at all getting a good steady idle. I'm not saying the werks plugs are not good plugs but for some reason I can't get a good tune with them. I'm sure my needle settings are off a little bit.