[mwebb]

there will not be spark at both electrodes , the spark will take the single easiest pathway to ground ,
which may vary as the gap erodes and conditions inside the combustion chamber change .

spark plugs with two and more electrodes were OEM specified by many , including VW Audi , Toyota - there was a difference in how the engines ran and overall emissions if the OEM recommendation / specification for spark plugs was not strictly adhered to .

but
on later current production VWs at least
the newest systems use only single electrodes , with multi strike spark

having said that
never use Bosch Platinum +4 or +2 spark plugs , they were never OEM specified for any system and do not perform as well as
the correct OEM specified part# for the system in question

Originally Posted by Piwoslaw

I read about Denso's TT spark plugs in a mag the other day and the principle seemed OK: The spark jumps between two tips, both have smaller than usual diameter which supposedly allows lower voltage, etc. Then the claims: Increased power, 5% lower fuel consumption. Yeah, right.