Just wondering on a 95 civic d16z, if the stock spark plugs are a 5 rating, should I jump up to a 6 or a 7? And if it is a 6, could I use the stock plugs off of a 94 lude vtec since it's a 6 rating, and what gaps for each of these? I've been told that I could use the stock d16z 5 ratings with a stock gap and it should be fine. Any thoughts or suggestions?

 

I wouldn't use the stock Prelude VTEC plugs because they are platinum. What do you plan to do with the car? If you are planning any sort of FI then I would go to your local dealer and ask for P/N 98079-5714G (NGK ZFR-7F11). They are two steps colder than your stock plugs and they are copper.

 

The d16z is gonna be forced fed. Jeff from homemadeturbo.com said he's run many FI'd setups with stock plugs at with a stock gap and they've run fine. I was just curious as to opinions on this. I'll see how each one runs but I'd just like a bit more input. thanks