: Spark Plugs



Sean McDonald
01-04-04, 07:30 PM
I decided to put Bosch Platinum +4 plugs in my 94 STS. Well, the power has changed, I'm not sure if it's for the better though. It feels smoother, however, I wonder if the smootheness is due to a possible lack of power? Any body have any expereince with these plugs?

ellisss
01-04-04, 07:41 PM
I decided to put Bosch Platinum +4 plugs in my 94 STS. Well, the power has changed, I'm not sure if it's for the better though. It feels smoother, however, I wonder if the smootheness is due to a possible lack of power? Any body have any expereince with these plugs?
Yes. They are platinum electrode plugs with high nickel content steel ground electrodes (4 ground electrodes, spaced evenly around the insulator).

Unlike Bosch's original crappy platinum plugs, (the one's with a platinum electrode the width of a human hair), the +4's are very good.

They do not belong in your Northstar. Here's why:

AC/Delco double platinum plugs have platinum electrodes on both sides. Look closely at one and you'll notice that the ground electrode has the same platinum 'button' on it that the main electrode does. This offers longer life, and hotter spark.

Remember, any lessening of resistance to current flow through a spark plug will allow more of the coil's juice (once it gets through the coil terminal and plug wire) to flow to the ground electrode in the plug.

I'm sure many people here have seen fouling and poor performance using non-OEM plugs in a Northstar. I believe the +4 Bosch is good enough use reliably, but I don't suggest it.

YMMV, though. :lildevil:

--
Ellisss

Sean McDonald
01-04-04, 07:46 PM
YMMV? Umm...sure. So, basically I really am losing power? What is THE best plug I could put in the car?

Allante North *
01-04-04, 08:08 PM
Hey Sean,

Go with the AC Delco plugs that are specified for your Cadillac. You can't go wrong. Many folks are satisfied with the Bosch, but the AC's are what the Cadillac was designed and tested with.

Sean McDonald
01-04-04, 08:43 PM
Probably a good idea. Good chance that it won't cost me $17.99 CAD a pair like those damn Bosch's did!