On Sat, 12 Jun 2004, Ken Lewis wrote:

> Scenario 2(quad tip).
> To me, if you provide four paths to ground then the impedance of the plug
> becomes R/4 since said paths are in parallel. Substituting into above
> formula you get Power=4*V^2/R or four times the power is required from the
> coil.

It doesn't work that way.

An air gap is very high resistance (almost infinite) until it ionizes,
then it becomes a very low resistance path.  In a multi-tip plug, one of
the paths will ionize first, and all the current will go through that
path.

David Brodbeck, N8SRE
'86 Volvo 240DL wagon
'82 VW Vanagon Westfalia Diesel (ebay #2481476461)