Twin-ground electrode spark plugs

[Lord_Anarchy]

As just about any Toyo owner/tech/enthusiast knows, the newer Toyo engines (dunno how far back they begin asking for it, although I could have sworn my 1994 5SFE says I should too) ask for these "twin-ground" plugs.

So, fast forward to my dilemma. I bought NGKs, single elec., for a 1999 Corolla LE (1ZZ-FE) and after that, it seems like it runs fine BUT if I fire up the AC, the extra load puts more work on the engine and that's where you can see little sparks coming from the DIS box or whatever you want to call the place where a distributor would be at. Would that be from worn plugs or is there any adverse effects to not heading Toyota's sticker of "Twin-ground electrodes"? The sparks are right where the spark plug cables connect to the iginiton system. I added some electric grease and noticed that cylinder four had red "rusty looking and colored" stuff on the boot of the plug wire.

Hopefully, with the answers of the PROS and CONS of not using twin-ground electrodes come to light, others can simply search

P.S. My '94 5SFE has IK20 Denso Iridiums, single, with NO problems at all.

[Zandro]

It`s much better with a high quality singel electrode plug
like Denso Iridium IK20 instead of a twin electrode plug.
Twin electrode plugs have an higher voltage requierment
than the singel electrode ones, and also the twin electrodes
"steals" the heat enegry created by the spark, and reducing ignitability.
i have tested a handfull of plugs on my car, not only twin electrode but
even quad electrode, and belive me it didnt help a bit, due to the increased
voltage requierments of the multi electrode plugs my engine started to build up carbon
so this is what i found out during my "research" German plugs are a no no, twin and quad
electrode plugs only results in carbon build up,unless you get hotter plugs,
NGK, Campion and Denso works fine. Then i discoverd that Denso had these iridium plugs end i went to my local toyota dealer and orderd a set for my car, i got a much smother idle, the car stoped jitering in cold contitions before the engine got normal temperature,
the iridium plugs also require 2000-5000v less than normal plugs to make a spark.
My 3S-FE engine and the Denso IQ20 plugs match like a pair of gloves.

[Mike Gerber]

Use exactly what your manual calls for:

Denso (formerly ND) PK20R11 or

NGK BKR6EP-11

I put the NGK's in my 94 5SFE a few years back simply becuse I could get them a bit cheaper. Both will work fine. Later versions (I believe generation 4 5SFE engines with distributorless ignition) require the double ground electodes.

Mike

[jackfrost1031]

you don't ahve to change double/triple/quad electrode plugs as often because of the distribution of carbon, but I don't see any other benefits.

But, if your manual specifies, by all mean go with it! Not like it's going to cost much more