Spark Plug - Usage

91porsche04
September 24, 1991


Model Group

911 turbo 2
1991-92

Part Identifier Number

2870 9103


Subject: Spark Plug Usage


ATTENTION: Service Manager/Service Technician

This bulletin replaces Technical Bulletin Group 2, Number 9103, dated 9-6-91.

Models Affected: 911 turbo 1991-92


Concern: 1991-92 911 turbo engines can be equipped with either WR 4 DPO or WR 6 DPO spark plugs. The WR 6 DPO spark plugs started in production July 1991. The WR 6 DPO spark plug is preferred for cars used on frequent short trips or cars that are infrequently run since this plug reaches a self-cleaning temperature more quickly than the WR 4 DPO.

The WR 4 DPO and the WR 6 DPO can be used interchangeably, but they must not be mixed on an engine.

Parts Information: WR 4 DPO - Part Number 999 170 186 90
WR 6 DPO - Part Number 999 170 190 90