Technical Service Bulletin Spark Plugs

Subject: Spark Plugs              Models: 912 ALL/911 ALL/911 Turbo

Bulletin Number: 85 – 08

Below is a listing of all tested and approved spark plugs.

Type/Model                                       Make                                                    Type                      Electrode Gap in mm

912 1966-69                                Bosch Champion                             W6BC                      0.6-0.7                                                                                                                   L82Y                        0.6-0.7
912E 1976                                     Bosch                                               WR7DC                    0.7 +0.1                                                                                                                                                           -0
911, 1965-68                                 Bosch                                              W4DPO                    0.55 911L                                                Champion                                       N6YC                        0.70
911S 1966-68                                Bosch                                               W3DPO                   0.55
911T 1969-71                                Bosch                                               W5DC                      0.60
911E 1969-71                                Bosch                                               W3DPO                   0.55 911S
911T 1972-73                                 Bosch                                              W5DPO                    0.55
911E 1972-73                                 Bosch                                              W36DPO                  0.55 911S
911 1974-77                                    Bosch                                              W5DPO                   0.55
911S 1974-77                                  Bosch                                              W5DPO                   0.55
911 1976-79                                    Bosch                                               W3DPO                  0.60 Turbo
911SC 1978-79                                Bosch                                                W5DC                    0.7+0.1                                                                                                                                                            -0
911 1984-86                                     Bosch                                                W8DC                   0.7+0.1                                                                                                                                                            -0 Carrera                                                                                                                                        0.7+0.1                                                                                                                                                             -0                                                                                                                                                        0.7+0.1                                                                                                                                                              -0
911 1986                                             Bosch                                                 W3Dp                   0.7+0.1 Turbo                                                                                                                                                    -0


  • Spark plug tightening torque: 30 Nm/21.6 ft. lbs.
  • It is recommended to lubricate the threads of spark plugs lightly with graphite grease (Molykote paste HTP white), or equivalent, prior to installation. Make sure paste is kept off the electrode and inside of the spark plug!

Bosch Platinum Spark Plugs

Spark plugs designated with the letters “DPO”, or W3DPO on the new Bosch spark plug Designation System correspond with the conventional design platinum spark plugs from the old system which were W28OP21.

Spark plugs with the letters “DP” or CP or W5DP or W3CP are platinum spark plugs of the new design with a sintered center electrode. These spark plugs must not be installed when conventional design platinum spark plugs “P21” or “DPO” only are specified.

Bosch Spark Plugs


spark plug

Platin – old (DPO)

spark plug 2

Platin – new (DP or CP)                      

spark plug 3

home page:

Want More?

Get the coolest tips and tricks today

Subscribe to our email list and get regular notifications of new videos and blog articles on how to repair your own car.