Autolite Copper Spark Plug 258

Autolite 258 is a copper non-resistor spark plug built for quick starts, smooth acceleration, and efficient combustion. It is an OE-style replacement with form, fit, and function intended for a wide range of foreign and domestic applications.

Key Features

Copper center electrode for responsive ignition performance.
Non-resistor design with 1 ohm resistance.
Tapered nickel ground electrode for consistent spark delivery.
Flat seat, 14.0 mm thread diameter, and 0.374 in. reach.
Short ceramic insulator with a 0.025 in. pre-gap.

Product Details

The Autolite Copper Non-Resistor Spark Plug line focuses on OE-style replacement value with practical ignition performance. Part number 258 uses a standard/regular center electrode design, nickel tip materials, and a stud terminal to support reliable electrical connection. For buyers searching for an Autolite 258 spark plug for ignition service, this plug matches common service requirements where a copper-core design and non-resistor construction are specified. It is also a fitment-relevant choice for applications that call for a flat-seat spark plug with a 3/4 in. hex.

Autolite positions this spark plug as a direct alternative to OE plugs, and the brands aftermarket and OE supply background supports consistent manufacturing standards. This part cross-references AP Exhaust 7542 and DENSO Auto Parts 5628 for the same application.

What It Helps Address

Hard starting caused by worn or inefficient spark plugs.
Rough idle from inconsistent ignition output.
Sluggish throttle response during acceleration.
Reduced fuel economy from degraded spark performance.

Installation Notes

Verify thread diameter, reach, seat type, terminal style, and pre-gap before installation. Use the specified gap for the engine application and inspect the ignition system for wear or contamination during service. Confirm the correct Autolite 258 spark plug specification before installation on any vehicle.