NGK 5858 Spark Plug

NGK V-Power Spark Plug 5858 Overview

NGK 5858 is a V-Power spark plug built for OE-style ignition performance in a wide range of classic domestic applications. It uses a copper core center electrode, nickel center and ground electrode tips, and a standard ground configuration to support consistent spark delivery and reliable combustion.

Compatible With Chrysler New Yorker, Newport, Town & Country, Dodge Monaco, Charger, Challenger, Oldsmobile Cutlass, Delta 88, 98, Toronado, Pontiac GTO, LeMans, Firebird, and other listed applications, this NGK spark plug is a direct-fit choice for many vintage V8 and inline engine setups. Part number 5858 is also referenced as XR4.

Key Features

• NGK V-Power Spark Plug line for OE-style ignition service
• Copper core center electrode for stable heat transfer
• Nickel center and ground electrode tip materials
• Standard ground electrode design with one ground electrode
• 5000 ohm resistance for ignition system noise control
• 14 mm thread diameter, 3/8 in. reach, and flat seat design
• Pre-gapped at .040 in. with a 13/16 in. hex size

Product Details

NGK builds this spark plug to meet original-equipment style requirements across domestic and import vehicle coverage. The V-Power design is aimed at maintaining dependable ignition performance while matching the fitment and heat range needs of many older Chrysler, Dodge, Oldsmobile, Pontiac, Chevrolet, Buick, Cadillac, and Jeep applications. The manufacturer heat range is 4, and the non-removable nut terminal supports standard ignition wire connections used in many classic vehicles.

For buyers searching for an NGK 5858 spark plug, XR4 replacement, or an OE-equivalent spark plug for classic Chrysler New Yorker and Pontiac GTO applications, this part offers the dimensions and electrode construction needed for proper service. This part cross-references Champion Spark Plug 58 and 58S for the same application.

Common Issues This Spark Plug Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire conditions related to aged ignition components
• Reduced combustion efficiency in older engine platforms
• Service replacement needs for OE-style tune-ups

Installation Notes and Tips

• Verify the vehicle’s required gap before installation; listed applications include 0.035 in., 0.040 in., and 0.045 in. specifications depending on engine and model year.
• Confirm thread diameter, reach, and seat type match the cylinder head before installing.
• Use the correct spark plug socket for the 13/16 in. hex.
• Inspect ignition wires, cap, and rotor during service to help maintain consistent spark output.
• Always follow the vehicle service manual for torque and gap specifications.

Quality Assurance

NGK is a major OE supplier and spark plug manufacturer with more than 80 years of automotive experience. The brand’s North American and global manufacturing and distribution network supports consistent product availability and OE-level production standards for ignition service.