Q'ers- In my experience, both my '86 Golf and '88 5000 expressed displeasure when fitted with plugs that were not the tri-electrode type. Assuming that there's a trend here, the 911 biturboquattro i will no doubt someday own (shortly after winning the lotto) will probably behave the same way. Just my $98,000.00 worth ;) '65 Matt '88 5000tq