Spark plug having a particular resistor

Spark plug having a platinum tip on an outer electrode

Spark plug having a plurality of center electrodes

Spark plug having a plurality of vertical ground electrodes and

Spark plug having a protective titanium thereon, and methods...

Spark plug having a reduced lead glaze layer on the...

Spark plug having a spark discharge portion with a specific comp

Spark plug having a specific structure of noble metal tip on...

Spark plug having a sub-combustion chamber for use in fuel ignit

Spark plug having a welded electrode and the method of...

Spark plug having an ablative coating for anticontaminat fouling

Spark plug having an erosion resistant tip

Spark plug having an internal conductor configuration

Spark plug having an oil film on an intermediate portion of...

Spark plug having arc-shaped precious metal chip and method of p

Spark plug having center electrode with columnar portion and...

Spark plug having combined surface and air gaps

Spark plug having dual gaps

Spark plug having dual gaps for internal combustion engines

Spark plug having electrodes shaped to produce a hollow spark co