Bosch Spark Plug for Porsche 911SC/928 (1978-1979)

This Bosch Spark Plug is a direct replacement for the Porsche 911SC and 928 applications listed in the fitment table below. Correct spark plug specification matters on these engines for clean combustion, steady idle quality, and consistent ignition service intervals. Bosch has been a global leader in automotive technology since 1886, pioneering innovations like electronic fuel injection and oxygen (lambda) sensors that shaped modern engine management. Today, Bosch supplies OEM-quality sensors, engine electronics, ignition components, and braking parts found in vehicles worldwide. Known for precision engineering and reliable performance, Bosch parts are built to factory specifications for dependable fitment and long-term durability.

Technical Details

• Manufacturer part number: 7905
• Bosch trade number: WR8DC+
• Thread diameter: 14 mm
• Reach: 19 mm
• Seat type: Flat
• Resistor value: 6 kOhm
• Preset gap: 0.8 mm

Fitment & Compatibility

Use the fitment table below to confirm your exact 911SC or 928 year before ordering. Plug specification should always be matched to the engine you are servicing.

If you’re unsure about plug selection before ordering, send us your VIN or engine details and we’ll confirm it. We’ve been handling Porsche ignition and tune-up components for over 20 years, and we take fitment verification seriously because it prevents mistakes.