Copper, Copper, Copper.

Resistor plugs
 

Found this to be an interesting topic so I checked my Haynes for 1971 250C and found on page 93 I see a under the spark gap specs that for the gap for M130 engine standard (non-resistor) plugs to be 0.028 to 0.032 in., while resistor type plugs are to be set at 0.035 to 0.039 in.
Would the change in gap change the effective resistance?
Perhaps the info is directed to engines with electronics??
Flintg

resistor plugs
 

I went back and carefully read the notice from Roy an noted he if refering to "many" not all MB applications. So his comment to check carefully is appropriate and I would imagine it applies to late model cars,but it is an interesting topic.
Thanks Roy
Flintg