Date: Sun, 30 Nov 2003 01:35:38 +0000 From: Grunff <grunffnopsam.com> Subject: Re: NGK Spark Plug Question
jon banquer wrote: > What is the difference between NGK BCP5EV, NGK BCP6EV and > NGK BCP7EV ? > > I have a 91 900S 16V non-turbo. The car currently has BCP6EV's. > How do I know which one is right ? The car is completely stock. Temperature - more specifically, the distance between the base of the porcelain insulator and the main plug body. The longer this is, the hotter the plug runs. Plug temperature is very important, especially in a high compression ration engine, and doubly so in a turbo. Too cold, and the plug will foul easily because it won't burn off accumulated crud. Too hot, and you'll get predetonation. Your car needs NGK BCP7EV. You can get away with NGK BCP6EV, but definitely the 5. -- Grunff