What about NGK & Denso Iridiums ? Are these just marketing gimmicks?

Can a real "tiny" electrode of Iridium along with the "U-groove" really make a difference?

Stu Ritter/MBCA "The STAR" Technical Editor, cautions that any motor with aluminum heads, needs to have their spark plugs at lease removed at least every 30K miles (he prefers 15K for BOSCH copper cores) otherwise the spark plug could be frozen in place.

Cars with 100K spark-plugs change intervals are having a hard time removing them without damage.

Comments?

:-) neil
1988 360TE AMG
1993 500E