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$4.99

NGK Standard spark plugs (in the iconic NGK ‘yellow box’ packaging) are a proven OE cornerstone and technology customers have relied on for decades. Engineered specifically for OE applications, NGK Standard spark plugs provide OE quality nickel alloy reli

Product Features:

ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode provides consistent performance
RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric 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
TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal

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$5.79

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

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$3.49

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite continues to set the standard. Designed and engineered in the USA, these spark plugs feature a copper cored center electrode for higher thermal conductivity and a specially engineered high nickel alloy center and ground electrode for extended life. The high alumina ceramic ensures high dielectric strength, while the leak-proof, heat-fused internal seal guarantees durability. Additionally, the multi-rib insulator prevents flash-over, making these spark plugs a reliable choice for any vehicle.

Product Features:

Copper cored center electrode for higher thermal conductivity
Specially engineered high nickel alloy center and ground electrode for extended life
High alumina ceramic for high dielectric strength
Leak proof, heat fused internal seal for durability
Multi-rib insulator prevents flash-over
Quick Starts and Smooth Acceleration: Designed to deliver quick starts and smooth acceleration, ensuring a reliable performance for your vehicle.
Enhanced Fuel Economy: Engineered to provide good fuel economy, helping you save on fuel costs.

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$2.79

U-Groove design provides better ignitability for increased engine efficiency.

Product Features:

Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
Wide range of part numbers for thousands of applications, including classic and collector cars
Lasts twice as long as most conventional plugs
100% pre-fired to assure reliable operation
U-Groove Conventional

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Dependable Performance, OE Replacement, RN14YC. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. The Copper Plus design ensures dependable performance and durability, while the copper core center electrode allows for accurate control of heat range, extending the spark plug’s life. Built to ISO and SAE standards, it offers superior corrosion resistance and proven performance. The nickel center electrode tip and flat seat type further enhance its reliability, making it a top choice for maintaining your engine’s 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
Reliable Nickel Center Electrode Tip: Featuring a nickel center electrode tip and flat seat type, this spark plug enhances reliability and helps maintain your engine’s efficiency.

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$4.79

With over 100 years of engineering expertise and more than 11 billion plugs sold, Autolite Platinum spark plugs are designed and engineered in the USA to deliver exceptional performance. Featuring a high nickel alloy side electrode that maintains a precise gap and a full platinum tip that ensures virtually no gap erosion, these spark plugs offer long-lasting durability. The necked-down center electrode fires quicker and cleaner with less voltage, resulting in easier starts, quicker acceleration, and improved fuel economy compared to standard plugs.

Product Features:

High nickel alloy side electrode maintains precise gap
Full platinum tip assures virtually no gap erosion for long life
Necked-down center electrode fires quicker, cleaner with less voltage for easier starts, quicker acceleration and improved fuel economy (as compared to standard plugs)
Improved Fuel Economy: Designed to enhance fuel efficiency compared to standard spark plugs.
Engineered in the USA: Backed by over 100 years of engineering expertise and a legacy of more than 11 billion plugs sold.

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$3.99

Champion® Platinum Power spark plugs deliver powerful performance with their premium design. Featuring a platinum center electrode for long life and a fine-wire center electrode for greater ignitability, these spark plugs ensure optimal engine performance. The V-trimmed ground electrode promotes sharper spark focus, while the exclusive Heat-Active alloy allows the electrodes to reach optimal temperature. Additionally, the platinum-tipped center wire resists wear and helps maintain the proper gap specification throughout the life of the plug. With a flat seat type and integrated resistor, this spark plug is an ideal OE replacement.

Product Features:

Platinum Power- Premium Spark Plug. Powerful Performance.
Platinum center electrode for long life
Fine-wire center electrode for greater ignitability
V-trimmed ground electrode promotes sharper spark focus
Heat-Active alloy allows electrodes to reach optimal temperature
Platinum tipped center wire resists wear and helps to maintain proper gap spec over life of the plug
Integrated Resistor and Flat Seat Type: Equipped with an integrated resistor and flat seat type, making it an ideal OE replacement for various engines.

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$11.99

Increased performance with World’s smallest Iridium Center Eletrode (0.4mm).

Product Features:

World’s smallest Iridium Center Electrode (0.4mm) for improved spark for maximum combustion
Patented 360-degree laser welding assembly process
U-groove and taper cut ground electrode to maximize flame propagation.
Withstands temperatures greater than 4000┬░ Fahrenheit
Burnished nickel plating for high temperature endurance and superior corrosion resistance
Wide range of part numbers for thousands of applications, including classic and collector cars
Iridium Power
Superior Performance: Patented technology allows the Iridium Power plug to outperform any other spark plug on the market, delivering more horsepower and better fuel efficiency.
Low Voltage Requirement: Requires 5,000 volts less to fire compared to conventional spark plugs, making it highly efficient and reliable under extreme conditions.
Enhanced Engine Starts: Experience faster and easier engine starts with fewer misfires, even under heavy loads, thanks to the advanced design of the DENSO Iridium Power spark plug.
Durable Iridium Material: Constructed with a durable iridium center electrode tip and a flat seat type, ensuring long-lasting performance and reliability.

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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.

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$5.79

Twin-Tip design enables faster flame propagation for more complete combustion.

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$10.99

Durability of an OE style plug combined with Power & Torque of high performance.

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 & Torque of high performance.
Withstands temperatures greater than 4000┬░ Fahrenheit
Iridium TT
Enhanced Fuel Economy and Lower Emissions: Drive around the Earth over 4 times with improved fuel efficiency and reduced emissions.
Reliable and Durable: The flat seat type design ensures a secure fit and consistent performance throughout its lifespan.

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Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, Autolite Double Platinum spark plugs feature platinum-to-platinum firing which virtually eliminates gap erosion, reduces misfires and increases durability of the plug. Consider upgrading to Autolite Iridium XP spark plugs for increased performance.

Product Features:

Works to optimize engine performance for a longer life and improved fuel economy
OE design
Full-platinum tips; platinum on both the center and side electrodes to promote reduced gap wear
Platinum ball welding process provides a consistent point of contact for enhanced adhesion

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$8.29

ACDelco Gold (Professional) Double Platinum Spark Plug are a high quality alternative to Original Equipment (OE) parts. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. 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:

One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal that helps reduce radio frequency and engine interference, regulate spark plug energy, and protect against compression pressures for long life
Double platinum point pad on center and ground electrode offer excellent durability and consistent voltage demands to help reduce wear on ignition system
Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
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

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$11.99

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

1991 Rolls-Royce Silver Spirit Spark Plugs

Spark Plugs for Your 1991 Rolls-Royce Silver Spirit

NGK – OE Series Standard Nickel Spark Plug: Conventional Tip Design, BPR5ES (Part No.7734)

NGK – G-Power Spark Plug: Single Platinum Tip Design, BPR5EGP (Part No.7082)

Autolite – Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration (Part No.65)

DENSO – U-Groove Spark Plug: OE Performance, lasts 30K+ Miles, W16EXR-U (Part No.3031)

Champion – Copper Plus Spark Plug: Dependable Performance, OE Replacement, RN14YC (Part No.405)

Autolite – Platinum Spark Plug: Fires Cleaner, Easier Starts, Quicker Acceleration (Part No.AP65)

Champion – Platinum Power Spark Plug: Powerful Perfromance, OE Replacement, RN14PMC (Part No.3405)

DENSO – Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, IW16 (Part No.5305)

NGK – Iridium IX Spark Plug: Single Iridium Fine Wire, BPR5EIX (Part No.6597)

DENSO – PW16TT Platinum TT Spark Plug (Part No.4501)

DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, last 100K+ Miles, IW16TT (Part No.4708)

Autolite – Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life (Part No.APP65)

ACDelco – Double Platinum Spark Plug (Part No.41-828)

NGK – Spark Plug (Part No.95525)

FAQs for 1991 Rolls-Royce Silver Spirit Spark Plugs

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