Bosch 999-170-179-90 Copper Nickel Spark Plug - WR5DC+

The Bosch 999-170-179-90 (also known as Bosch 7992 or WR5DC+) is a high-quality copper-nickel spark plug engineered to deliver reliable ignition and lasting performance. This OE-replacement spark plug is commonly used in European vehicles, particularly Porsche and Audi models, as well as various powersports applications.

Key Features:

• Heavy-duty yttrium-enhanced nickel center electrode with copper core for superior reliability and heat dissipation
• Tapered cut nickel-chromium ground electrode improves cold-weather starting and ignitability
• Nickel-plated rolled threads provide anti-seize properties and corrosion protection for easy installation and removal
• Metal glass fused resistor (6K ohm) delivers maximum interference suppression
• Angular 5-rib insulator design prevents flashover and misfire due to current leakage
• Projected center electrode design optimizes flame kernel placement

Specifications:

• Thread Size: 14mm with 1.25mm pitch
• Reach: 19mm (3/4 inch)
• Hex Size: 13/16 inch (21mm)
• Seat Type: Gasket
• Gap: 0.031 inch (0.8mm)
• Terminal Type: Removable nut
• Resistor: Yes (6K ohm)

Installation Notes:

• Torque specifications: 15-29 lb-ft for cast iron heads, 15-22 lb-ft for aluminum heads
• No anti-seize compound needed due to nickel-plated threads
• Typical service interval: 10,000-30,000 miles for standard copper-nickel plugs

This spark plug meets or exceeds OEM specifications and provides excellent value for routine maintenance. Cross-reference numbers include OEM part numbers 999-170-165-90 and 999-170-179-90, as well as Bosch numbers 0242245552 and WR5DC.