Autolite 145 Spark Plug

Autolite 145 Copper Resistor Spark Plug

Autolite 145 is a copper resistor spark plug built for OE-style replacement needs across a wide range of Chevrolet and GMC trucks, vans, and utility vehicles. It is specified with a 0.040 in. pre-gap, 14 mm thread diameter, 5/8 in. hex, tapered seat, and stud terminal for straightforward service matching.

Key Features

• Copper core center electrode for quick starts and steady ignition performance
• Nickel center and ground electrode tip materials for standard service durability
• Resistor design with 4,000 ohms resistance to help reduce ignition noise
• 0.040 in. pre-gap for OE-style tune-up replacement
• Ceramic insulator with short insulator type for conventional ignition applications
• Tapered ground electrode tip design and single ground electrode configuration

Product Line Details

Autolite Copper Resistor Spark Plug products are positioned as OE-form, fit, and function replacements for many domestic and foreign applications. The copper core design supports responsive ignition performance, while the resistor construction helps maintain cleaner electrical operation in systems that call for suppression-type plugs.

Detailed Description

This Autolite spark plug is a practical replacement choice for older Chevrolet C10, K10, P30, and GMC Jimmy, P2500, and P3500 applications where OE-style dimensions and gap specifications matter. Part number 145 is also cross-referenced to Champion 121 for the same application. The plug’s tapered seat, 14 mm thread, and 5/8 in. hex make it a direct-service style component for many classic GM ignition systems.

Common Issues It Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire symptoms related to excessive plug wear
• Reduced throttle response during acceleration
• Ignition noise concerns in resistor-plug applications

Installation Notes and Tips

Verify the required gap and seat style before installation, since fitment notes include both 0.035 in. and 0.045 in. OE-style applications across different Chevrolet and GMC models. Confirm the vehicle’s ignition system requirements, especially on older trucks and vans where some applications note heavy-duty use or non-HEI compatibility. Use the listed fitment details for 1970-1990 Chevrolet and GMC applications, including Chevrolet C10, K20, P30, and GMC C2500, K3500, and Jimmy models.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment channels, with a focus on OE-style form, fit, and function. Part number 145 is built to meet standard service expectations for replacement spark plugs in supported Chevrolet and GMC applications.