RE: BTDT: Bosch Platinum +4 Plugs

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

... not to be particularly contrary about this, but assuming that the old
plugs were in need of replacement you might very well have noticed the same
results if you had simply replaced the plugs with the same type of plugs
that you removed.  What would be a good test would be to renew the plugs
with the ones that are now being used, and then to swap to the newer design
and compare the differences ...

I don't by any means consider myself to be an expert on the subject, but as
has been discussed on the list before, it is my understanding that in
general the primary expected improvement is in the overall service life of
the plugs.  The multiple ground electrodes provide a large number of points
that are nominally at a proper gap from the center electrode.  Once a
particular area has been burned back to increase the gap there will be some
other area of the plug at a proper gap for the spark.  I do not believe that
the electrode material provides any better characteristics to the spark
itself other than perhaps more resistance to having the material be eroded
away by the spark process.  The only real difference I'm aware of is the
orientation of the spark within the cylinder.

Steve Buchholz
San Jose, CA (USA)

	----------
	I've run a set of Bosch Platinum +4s in my Turbo Volvo (2.3L 20v
intercooled
	5cyl.) for 1200 miles so far so good.  Does start easier and idle
smoother, and
	I may be getting 1 or 2 mpg better (its really to early to tell).