1958 Buick Roadmaster Spark Plugs

DiamondFire Automotive Spark Plug delivers exceptional performance and efficiency with its innovative Diamond Fire edge-to-edge ground electrode design. Engineered for smoother acceleration and idle, it ensures a faster, more complete burn of the fuel charge, maximizing pressure against the piston and putting more fuel to work. With power output improved by up to 6% on average, this spark plug enhances energy efficiency while reducing engine carbon deposits thanks to its patented Diamond Fire Technology. The unique diamond-shaped side wire electrode ignites the air/fuel mixture quickly, creating a larger flame kernel for optimal combustion. Crafted with durable nickel center and ground electrode tips, it offers long-lasting reliability. Pre-gapped at the factory for hassle-free installation, this tapered seat spark plug is a smart choice for drivers seeking improved fuel savings, cleaner engine performance, and enhanced power output.

Product Features:

• E3’s Diamond Fire edge to edge ground electrode provides maximum performance with increased efficiency and a faster more complete burn.
• Smoother Acceleration & Idle – The faster flame initiated by the spark plug results in a more complete burn of the ingested fuel charge. More pressure is created against the piston more fuel is put to work
• Energy – Power output improved up to 6% on average in the typical operating ranges. Results will vary.
• Efficiency – The “diamond shaped” side wire electrode projects the combustion spark in a way that more quickly ignites the air/fuel mixture, thereby creating a significantly faster and larger flame kernel. The result is that more fuel is put to work durin
• E3’s patented Diamond Fire Technology provides a cleaner burning combustion, which translates into fuel savings and reduced engine carbon deposits
• The Spark Plugs are pre-gapped at the factory and cannot be adjusted.

The Iridium TT Spark Plug combines the durability of an OE-style plug with the power and torque of high-performance engineering, making it a standout choice for drivers seeking reliability and efficiency. Featuring a 0.4mm Iridium center electrode – the world’s smallest diameter – it maximizes firing potential, while the 0.7mm needle tip ground electrode promotes higher spark energy and minimizes heat quenching. Built with DENSO’s patented Iridium-Rhodium alloy formula, it boasts the highest concentration of Iridium for unmatched durability, withstanding temperatures over 4000 Deg F. The advanced Twin-Tip Technology pairs a fine wire Iridium center electrode with a needle tip Platinum ground electrode, ensuring superior ignition and fuel efficiency. Designed to enhance fuel economy and reduce emissions, this spark plug allows you to drive farther with fewer stops. Developed to original equipment specifications and utilizing a 360-degree laser welding process, it guarantees exceptional structural strength and consistent performance. Perfect for those who demand endurance and power in every drive.

Product Features:

• 0.4mm Iridium Center Electrode: World’s Smallest Diameter that maximizes firing potential
• 0.7mm Needle Tip Ground Electrode: Promotes higher spark energy and less heat quenching
• DENSO Patented Optimized Iridium-Rhodium Alloy Formula: Highest concentration of Iridium vs. competitors for greater durability
• DENSO Patented 360 degree laser welding process: Ensuring exceptional quality bond and structural strength with the Iridium Center Electrode
• Durability of an OE style plug combined with Power and Torque of high performance.
• Withstands temperatures greater than 4000 degree Fahrenheit
• Iridium TT
• Advanced Twin-Tip Technology: Combines a Fine Wire Iridium Center Electrode with a Needle Tip Platinum Ground Electrode for superior ignition and efficiency.
• Enhanced Fuel Economy and Lower Emissions: Designed to provide better fuel economy and reduced emissions, allowing you to drive around the Earth over 4 times.
• Original Equipment Specification: Developed from the Super Ignition Plug (SIP) design, ensuring reliable and consistent performance.

Autolite Platinum spark plugs are crafted for superior performance and durability, making them ideal for older engine applications. Featuring a platinum center electrode firing tip, these spark plugs ensure quicker firing, smoother starts, and enhanced acceleration while improving fuel efficiency. The platinum firing tip prevents gap erosion, extending the service life, while the high alumina ceramic insulator provides excellent thermal conductivity and insulation for added strength. A multi-rib insulator design prevents flash-over, and the nickel-plated shell resists corrosion for long-lasting reliability. With a tapered seat type, these spark plugs deliver enhanced performance and durability, ensuring consistent ignition. Designed with a mid-projection standard center electrode and nickel ground electrode tip, they are built for performance-grade applications. Equipped with a resistor, these spark plugs offer reliable functionality and are a dependable choice for maintaining engine efficiency over time.

Product Features:

• Engineered with a platinum firing tip that prevents gap erosion for longer service life.
• Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
• The multi-rib insulator prevents flash-over.
• Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
• Tapered Seat Type: Enhances performance and durability for a longer-lasting spark plug.

ACDelco Gold (Professional) RAPIDFIRE Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These RAPIDFIRE Single Platinum Performance Spark Plugs are designed for everyday use and are a high quality replacement for many vehicles on the road today. These premium aftermarket spark plugs have high-quality suppressors that help prevent misfiring, an improved plug to boot seal, and a pure copper core for greater durability. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:

• Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
• Pure copper core provides great heat transfer and helps maximize plug durability
• Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
• Ribless insulator helps optimize plug to boot sea
• Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
• Premium aftermarket replacement part
• Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
• High-Quality Suppressors: ACDelco Gold RAPIDFIRE Spark Plugs feature high-quality suppressors that help prevent misfiring, ensuring reliable performance for everyday use.
• Improved Plug to Boot Seal: Designed with an improved plug to boot seal, these spark plugs provide a secure fit, enhancing overall engine performance and longevity.

This spark plug non fouler is designed for easy installation on specified vehicles to protect spark plugs from fouling and damage. It is engineered for durability and reliable performance.

Product Features:

• Direct replacement – this spark plug non fouler is designed for easy installation to protect spark plugs from fouling and damage on specified vehicles
• Ideal solution – this non-fouler preserves spark plug life and is a reliable replacement for an original non-fouler that has failed due to corrosion
• Durable construction – made from quality components to ensure reliable performance and a long service life
• Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience

Double Platinum Spark Plug by Motorcraft is the ultimate choice for maintaining peak performance and reliability in your Ford, Lincoln, or Mercury vehicle. Engineered to meet strict Ford standards, these spark plugs feature platinum center and ground electrode tips for exceptional durability and resistance to oxidation and arc erosion. Designed to eliminate misfires, reduce fuel consumption, and optimize emissions, they ensure smooth engine operation while protecting against false check engine lights. The multi-rib insulator adds an extra layer of protection against misfires, while the exact fit guarantees seamless installation. With service intervals of up to 100,000 miles, these spark plugs deliver long-lasting performance and value. Backed by Motorcraft’s Service Parts Warranty, they are crafted with high-quality materials to provide reliable performance across a wide range of domestic and import applications. Choose Motorcraft spark plugs for the same trusted quality that was in your vehicle when it rolled off the assembly line.

Product Features:

• Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
• Backed by Motorcraft’s Service Parts Warranty
• Exact fit for Ford, Lincoln and Mercury vehicles
• Resistant to oxidation and arc erosion.
• Multi-rib insulator protects against misfire.
• Service intervals of up to 100,000 miles.
• Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
• Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
• Motorcraft ignition components help prevent false check engine lights.

The Copper Plus spark plug is engineered for dependable performance and durability, making it an ideal choice for maintaining engine efficiency. Featuring a copper core center electrode, it ensures accurate heat range control for extended lifespan and consistent wear. Its nickel center electrode tip enhances durability and reliability, while the tapered seat type design guarantees a secure fit and optimal performance. Built to ISO and SAE Standards, this spark plug offers proven performance and superior corrosion resistance, ensuring long-term reliability. As an OE replacement, it delivers the quality and functionality needed to keep your vehicle running smoothly. Whether you’re seeking improved conductivity or heat control, this standard-grade replacement spark plug is designed to meet your engine’s demands with precision and efficiency.

Product Features:

• Copper Plus – Dependable Performance and Durability
• Copper core center electrode allows for accurate control of heat range for longer life
• Superior corrosion resistance
• Built to ISO and SAE standards for proven performance
• Built to ISO and SAE standards for proven performance
• Nickel Center Electrode Tip: Equipped with a nickel center electrode tip, this spark plug offers superior durability and reliable performance, making it a dependable choice for maintaining engine efficiency.
• Tapered Seat Type: The tapered seat type design of the Champion Copper Plus Spark Plug ensures a secure fit and optimal performance, contributing to the overall reliability of your engine.
• OE Replacement: Designed as an OE replacement, the Champion Copper Plus Spark Plug guarantees dependable performance and durability, making it an ideal choice for maintaining your vehicle’s engine.

NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode’s durability is six times harder than platinum. Iridium alloy’s extremely high melting point is perfect for today’s engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug.

Product Features:

• SINGLE IRIDIUM TIP: Fine wire 0.6 millimeter iridium tip center electrode ensures high durability and a consistently stable spark
• IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
• TAPERED CUT GROUND ELECTRODE: Reduced quenching design produces outstanding ignitability, improved acceleration, fuel efficiency and durability
• SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
• TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
• RECOMMENDED USAGE: Modified or high performance applications, or as an upgrade to OE nickel alloy spark plugs

ACDelco GM Original Equipment Conventional Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These Conventional Spark Plugs are designed for reliability and efficient performance, and are a high quality replacement for many vehicles on the road today. Their high-quality copper cores and outstanding suppression characteristics deliver reliable performance. They are also available for Marine applications. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco GM Original Equipment parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional.

Product Features:

• Black Onyx coating helps reduce corrosion
• Copper core provides great heat transfer and helps maximize plug durability
• Ribbed suppressor seal extends resistance and helps prevent spark ‘flash over’ and misfires
• Nickel-chrome alloy sheathing helps prevent corrosion on center electrode
• Available for use in Marine applications
• Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
• ACDelco GM Original Equipment parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
• GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle

Copper Plus spark plug RJ12C delivers reliable performance and durability, making it an ideal OE-type replacement for your vehicle. Featuring a copper core center electrode, it ensures precise heat control for extended lifespan and consistent wear. The nickel-tipped center and ground electrodes enhance conductivity while resisting fouling, ensuring smooth engine operation. Built to ISO and SAE Standards, this spark plug offers proven performance and superior corrosion resistance, making it a dependable choice for maintaining your vehicle’s efficiency. With a flat seat type and integrated resistor, it is designed to meet the demands of modern engines while providing excellent value and long-lasting functionality.

Product Features:

• Resists fouling
• Superior corrosion resistance
• Dependable and proven performance
• Increased conductivity and heat control for good overall wear

NGK G-Power Platinum spark plugs are the best single platinum spark plugs at an economical price. G-Power plugs feature a fine wire platinum center electrode and a trapezoidal cut ground electrode that offers increased durability, improved fuel efficiency, lower emissions, faster starts and quicker acceleration over conventional nickel spark plugs. An excellent upgrade for vehicles which used nickel alloy spark plugs originally. For better performance consider upgrading to a NGK Iridium IX plug. For even greater performance consider upgrading to a NGK RUTHENIUM HX plug.

Product Features:

• SINGLE PLATINUM TIP: Fine wire 0.6 millimeter platinum tip center electrode ensures improved durability and a consistently stable spark
• PLATINUM ALLOY: G-Power platinum provides exceptional value with increased performance and longer service intervals than factory nickel plugs
• TRAPEZOIDAL CUT GROUND ELECTRODE: Reduces quenching design produces improved ignitability and performance
• SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
• COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
• RECOMMENDED USAGE: Lower cost alternative to double precious metal spark plugs or as an upgrade to OE nickel alloy spark plugs
• Trapezoidal Cut Ground Electrode: Improves fuel efficiency, lowers emissions, and provides faster starts and quicker acceleration.
• Economical Upgrade: Ideal for vehicles originally equipped with nickel alloy spark plugs, offering a cost-effective performance boost.
• Enhanced Durability: Designed to last longer than traditional nickel spark plugs, reducing the need for frequent replacements.

ACCEL’s patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark plug boot or dimpling the header tube. The shorter spark plug length also can make it easier to install an remove the spark plugs in certain applications where there is not a lot of room to fit a socket or move a wrench around. ACCEL Shorty Spark Plugs are made with a Copper core which is a better conductor than Platinum and Iridium. They deliver a stronger spark especially in high performance applications where high combustion pressures are present. Copper is much better at dissipating heat than other materials which lessens the chance of a misfire. ACCEL Shorty Spark Plugs are capable allowing you to open the gap exposing a larger flame kernel or close it if needed for high boost applications. All ACCEL Shorty Spark Plugs have machine rolled threads allowing for a more precise thread engagement and torque retention.

Product Features:

• Shorty Spark Plugs For Tubular Exhaust Headers
• Eliminates Dimpling Headers For Added Clearance
• Improves Spark Plug Access To Fit Socket Or Wrench
• Shorter Overall Plug Length Vs. OE Style Plug
• Copper Core Center Electrode
• Projected Tip
• Helps Eliminate Burned Spark Plug Boots
• Shorty Header Spark Plug

The Spark Plug with a standard center electrode design and durable nickel construction ensures reliable ignition performance for your vehicle. Featuring both a nickel center electrode tip and a nickel ground electrode tip, this spark plug is built for consistent conductivity and long-lasting durability. Its tapered seat type provides a secure fit, enhancing the overall efficiency of your engine. Designed to deliver dependable performance, this spark plug is an excellent choice for maintaining optimal engine operation. Whether you’re replacing a worn-out plug or performing routine maintenance, this high-quality component offers exceptional value and reliability.

Product Features:

• Standard center electrode design ensures consistent and reliable ignition performance.
• Nickel center and ground electrode tips provide excellent conductivity and enhanced durability.
• Tapered seat type offers a secure fit, improving engine efficiency and performance.
• High-quality construction supports long-lasting operation and dependable engine maintenance.
• Ideal for routine maintenance or replacing worn-out spark plugs, ensuring optimal engine functionality.

NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode’s durability is six times harder than platinum. Iridium alloy’s extremely high melting point is perfect for today’s engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug.

Product Features:

• SINGLE IRIDIUM TIP: Fine wire 0.6 millimeter iridium tip center electrode ensures high durability and a consistently stable spark
• IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
• TAPERED CUT GROUND ELECTRODE: Reduced quenching design produces outstanding ignitability, improved acceleration, fuel efficiency and durability
• SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
• TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
• RECOMMENDED USAGE: Modified or high performance applications, or as an upgrade to OE nickel alloy spark plugs
• Outstanding Acceleration and High Fuel Efficiency: NGK Iridium IX spark plugs are engineered to deliver exceptional acceleration and improved fuel efficiency, making them ideal for performance enthusiasts.
• Extreme Ignitability and Anti-Fouling: These spark plugs offer extreme ignitability and exceptional resistance to fouling, ensuring reliable performance in various driving conditions.

This spark plug non fouler is designed for easy installation on specified vehicles to protect spark plugs from fouling and damage. It is engineered for durability and reliable performance.

Product Features:

• Direct replacement – this spark plug non fouler is designed for easy installation to protect spark plugs from fouling and damage on specified vehicles
• Ideal solution – this non-fouler preserves spark plug life and is a reliable replacement for an original non-fouler that has failed due to corrosion
• Durable construction – made from quality components to ensure reliable performance and a long service life
• Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience

This spark plug non fouler is designed for easy installation on specified vehicles to protect spark plugs from fouling and damage. It is engineered for durability and reliable performance.

Product Features:

• Direct replacement – this spark plug non fouler is designed for easy installation to protect spark plugs from fouling and damage on specified vehicles
• Ideal solution – this non-fouler preserves spark plug life and is a reliable replacement for an original non-fouler that has failed due to corrosion
• Durable construction – made from quality components to ensure reliable performance and a long service life
• Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience