Spark plug question

How many? This guy has them listed as needed for Saab cars.

http://www.ebay.com/itm/4-NGK-V-Powe…-/150771779948

Sounds like a platinum series.

Short story is don't deviate from reccomendend plugs the FSM list. Both the Z and SC Frontier run like shit with crap plugs.

I just checked the FSM, (should have done that first) these are the recommended standard plugs for VG30ET

These are the plugs I have in my 86NA. They are standard NGK coppers with the V grove center electrode.
Here is how to decode NGK part numbers: http://www.ngksparkplugs.com/techinf…tnumberkey.pdf

Vehicle applications from the part look up on Rockauto (not always 100% perfect, but usually correct):

+1 on the v-groove. I am running these right now--they're the standard copper plugs just with a grooved tip. I only bought them because I couldn't find the regular copper ones without the groove. They seem to work the same.

According to NGK, the concept of the V groove is that it moves the spark closer to the edge of the electrode, better igniting the mixture. Here is a little diagram on their German site:
http://www.ngk.de/en/products-techno…ter-electrode/

My 84T ran like shit with Bosch platinum plugs, I tried them when they first came out and people were saying how great they were.
BCPR6E-11 is all i run now

Bosch plugs are shit. The 6E V-Powers are what I run in turbo cars, 5Es for NAs. I've never noticed a difference between the standard copper cores or V-Powers and since they're the same price I try and get the V-Powers.

Same experience with Bosch Platinum plugs here too, car ran like crap. Switched back to 6Es and never an issue since.
If you can't find the 6Es at the auto parts store you can get them in the lawnmower section of Home Depot - they also fit Honda mowers. lol

I've never had any luck with anything from Bosch on a Z31.

Denso is okay, had good results with AutoLite.

NGK copper plugs (v-power or regular) are best, currently running NGK V-Power plugs in the slicktop, with the NGK "blue" wire set.

I usually also stay away from iridium and platinum plugs.