Bosch 8505 Spark Plug

Bosch EVO Spark Plug for Modern Turbo Engines

The Bosch EVO spark plug is built for modern gasoline direct injection and turbocharged engines that demand stable ignition under high cylinder pressure. Bosch Part Number 8505 combines an iridium fine-wire center electrode, platinum ground tip, and a projected ceramic insulator to support consistent spark performance in demanding driving conditions.

Key Features

• Bosch EVO line engineered for long service life in advanced engines
• High dielectric strength rated above 45 kV to help resist irregular combustion events
• Iridium center electrode with fine-wire design for precise spark delivery
• Platinum ground electrode tip with J-gap configuration
• Resistor spark plug with 6,000 ohm resistance
• 12 mm thread diameter, 14 mm hex, flat seat, and 26.5 mm reach
• Ceramic insulator with projected tip design for modern ignition systems

Product Details

Bosch EVO Part Number 8505 is developed to meet the demands of today’s turbocharged gasoline direct injection engines, where ignition stability matters under heat, pressure, and load. The plug uses a copper core with an iridium center electrode and platinum ground tip to support reliable spark formation and consistent combustion. Bosch produces the EVO line to original equipment quality standards, making it a practical choice for drivers servicing vehicles such as the Honda Civic, Acura RDX, and Toyota Tundra with the correct OE-style application.

This part cross-references no listed aftermarket numbers in the provided data.

What It Helps Address

• Misfires caused by worn or heat-stressed spark plugs
• Hard starting from weak or inconsistent ignition output
• Rough idle in turbocharged or direct-injection engines
• Combustion instability under high load or elevated cylinder pressure
• Reduced spark efficiency from extended service intervals

Installation Notes and Tips

Verify the engine application by year, make, and model before installation. Confirm the 12 mm thread diameter, 14 mm hex, 26.5 mm reach, and flat seat match the original specification for the vehicle. Use proper spark plug service procedures, including checking the gap specification and tightening to the manufacturer’s torque recommendation.

Quality Assurance

Bosch manufactures the EVO spark plug line to OE-level quality standards and designs it for reliable ignition performance in modern engines. Bosch Part Number 8505 is engineered for long service life and consistent operation in demanding applications.