Priced each. Bosch is an original equipment supplier to Porsche.

As of the introduction dates listed below the factory is installing spark plugs with a changed heat range (more favorable cold-start behavior).

New: Bosch fr 7 ldc4 or beru 14 fr 7 ldu

Former: Bosch fr 6 ldc or beru 14 fr 6 ldu

As of 4/23/97, from engine number 65 v 09399

Effective immediately, if spark plug replacement becomes necessary, install the spark plugs with the newly approved heat range. Spark plugs must be of the same heat range in the engine. This applies to engines prior to the above mentioned introduction date.
Known as: spark plug 14fr 7 ldu