Autolite AP145 Spark Plug

Autolite Platinum Spark Plug AP145

Autolite Platinum Spark Plug AP145 is built for dependable ignition performance in a wide range of Chevrolet and GMC truck and van applications. With platinum center electrode materials, a resistor design, and OE-style form, fit, and function, this spark plug supports consistent starts, smooth acceleration, and stable fuel economy.

Key Features

• Platinum center electrode tip and core materials for added durability versus standard copper plugs
• Resistor type design with 4,000 ohms resistance
• Pre-gapped at 0.040 in. / 1.00 mm
• Tapered seat with 14 mm thread diameter and 5/8 in. hex size
• Ceramic insulator with short insulator type for OE-style fitment
• Nickel ground electrode with tapered tip design
• Autolite AP145 spark plug cross-references AMS Automotive 4000 and DENSO 5029 for the same application

Product Details

The Autolite Platinum Spark Plug line is positioned as an OE-style replacement choice for drivers who want factory-like fit and dependable ignition performance without moving away from a value-focused aftermarket part. AP145 uses platinum at the center electrode to improve wear resistance, while the nickel ground electrode and resistor construction help maintain steady spark delivery over time. This makes the Autolite AP145 a practical choice for older Chevrolet C10, K10, P30, and GMC Jimmy, C/K-series, and P-series applications where correct gap and ignition consistency matter.

Compatible With 1970-1990 Chevrolet and GMC truck, van, and utility applications listed in the fitment data, including 1975 Chevrolet C10, 1980 Chevrolet K10, 1987 Chevrolet R30, 1979 GMC Jimmy, and 1990 GMC P3500. Always verify the required gap and engine specification against the vehicle service information before installation.

Common Issues This Part Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Sluggish throttle response during acceleration
• Reduced fuel economy from degraded ignition performance
• Misfire concerns related to aged plug electrodes

Installation Notes and Tips

Check the vehicle-specific gap listed in the fitment notes before installation, since some applications call for 0.035 in., 0.045 in., or 0.025 in. gap settings. Confirm thread diameter, reach, and seat type match the engine specification, and inspect plug wires, distributor components, and ignition timing when replacing plugs on higher-mileage Chevrolet and GMC engines. AP145 is a direct-fit spark plug for the listed applications, but final setup should follow the engine’s service manual.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment channels, and the Platinum Spark Plug AP145 is built to OE form, fit, and function standards for the listed applications.