08-20-2009, 05:06 PM
Join Date: Aug 2008
It's funny how everyone thinks they are smarter than the engineers that designed the engine.
The underhood sticker tells the correct plugs to use - and the gap.
ALWAYS check the gap, the plug may have been dropped and the gap changed, or even mfrg differences can make a difference.
Torquing the correct plugs to spec also positions the ground electrode to the position it's "shadow" on the spark is minimized.
Use a touch of anti-sieze on the threads, and a touch of dielectric grease on the boots.
The correct Standard plugs may not last a million miles, but they'll give the best performance and mileage over the others.
I've heard, but haven't proved it yet - Plats fire OK on the compression stroke, but have a hard time firing on the waste spark - the polarity is reversed on the waste spark. The tiny wire electrode doesn't like the reversed polarity.
Emissions will go up, O2 sensors life is shortened, and cats fail too early.
I've never liked plats except where the heads were designed around them - like some Toyotas.
On an older conventional engine, Chev v8's etc., plats can be seen from across the room on a scope - they look like fouled plugs. Replacing them with "real plugs" makes a big difference.
It's no wonder the country is falling apart - stupidity abounds!