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$6.29

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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$4.79

Champion Platinum Power spark plugs deliver powerful performance. Made from exclusive Heat-Active alloy, a fine-wire center electrode and V-trimmed ground electrode provides sharp spark focus.

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

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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

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$9.79

ACDelco GM Original Equipment Double Platinum Spark Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. ACDelco GM Original Equipment parts are the true OE parts installed during the production 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:

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
Approved by US Legal 7/31/19
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
GM regularly updates production and service part designs to integrate new materials and technologies

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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

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$6.99

The Spark Plugs are the product of years of fundamental research in the combustion field. The unique patented electrode configuration of these new The spark plugs increases the amount of combustion pressure created during each power stroke of an engine, which results in a marked increase in power output, fuel economy, and reduced emissions in all gasoline engines. E3.48 is a 14mm, 0.750 reach plug with a gasket seat. It fits a wide variety of late model applications, especially import. E3.48 is widely stocked in automotive retail stores. The automotive plugs have three legs securing the Diamond FIRE electrode to the shell. This allows for excellent heat transfer, and helps to create more turbulence in the cylinder. The patented Diamond FIRE side wire is proven to increase power, reduce fuel consumption and improve hydrocarbon emissions in long-term use.

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 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.

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$4.99

Dependable performance. This Champion spark plug features a copper core electrode that provides increased conductivity and heat control for good overall wear.

Product Features:

Copper Plus – Dependable Performance.
Copper core center electrode allows for accurate control of heat range for longer life
Patented TinTac and ULTRASEAL coated shell for maximum corrosion resistance
Patented SAC-9 semiconductor resistor for maximum EMI & RFI suppression
Built to ISO and SAE standards for proven performance

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$4.99

Dependable performance. This Champion® spark plug features a copper core electrode that provides increased conductivity and heat control for

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

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$4.99

NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:

ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove 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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$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 reliable performance and design. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance, while triple gasket sealing prevents combustion gas leakage. Solid 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

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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$3.49

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:

Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
Multi-rib insulator reduces danger of “flash-over”
One-piece terminal post adds strength
Resistor reduces radio frequency interference (RFI) and electrode erosion

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$6.49

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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$4.79

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

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$8.99

Our best spark plug! Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, the Autolite Iridium XP spark plugs feature an iridium-enhanced 0.6mm finewire design and patented platinum sidewire technology to provide better overall durability and a more focused ignition for enhanced ignitability and performance. Features double Iridium-enhanced alloy technology center electrode for improved durability and wear resistance.

Product Features:

0.6 mm finewire design improves ignitability
Patented V-trimmed platinum sidewire technology resists wear
OE equivalent design is engineered for every engine
Designed for better overall durability with virtually no gap erosion

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$8.49

Champion® Iridium – the ultimate element. This spark plug’s fine-wire iridium center and platinum ground electrodes provide the sharpest spark focus for maximum performance.

Product Features:

Champion Iridium – Maximum Performance. Premium Spark Plug
Iridium center electrode delivers maximum life
Fine-wire center electrode and V-trimmed for greater ignitability
V-trimmed ground electrode promotes sharper spark focus
Maintains stable operating temperature under all engine loads
Heat-Active™ alloy allows electrodes to reach optimal temperature quickly

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$8.29

SPARK PLUG

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$7.99

Manufactured to the strictest OE performance, durability and emissions standards.

Product Features:

OE grade platinum on both center and ground electrods
Premium shell construction with machine-rolled threads
Superior thermal conductivity
Sustained spark performance over 60,000 miles
Reduced secondary required voltage, increased ignition efficiency
Satisfied customers, reduced shop comebacks
Double Platinum

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$4.34

The Bosch Super Plus Spark Plug utilizes an yttrium enhanced copper core center electrode, making it one of the longest lasting copper core spark plug on the market – by 50% versus even OE plugs. Bosch Super Plus also features a tapered, v-profile ground electrode for improved cold starts and better fuel ignitability. Center Electrode Core Material: Nickel-Yttrium and Copper – Center Electrode Tip Material: Nickel-Yttrium – Ground Electrode Tip Material: Nickel-Chromium

Product Features:

OE-Equivalent and direct fit application.
Heavy-duty yttrium-enhanced copper core center electrode.
Tapered, v-profile nickel chromium ground electrode.
Nickel-plated rolled threads.
Metal glass fused resistor.
Angular, five-ribbed insulator design.
Electrode gap is factory set and never requires adjustment.
Anti-seize and corrosion protection. Bosch Super Plus Spark Plugs deliver quality performance based on technology that’s proven on racetracks around the world in the most sophisticated racing engines

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$2.29

Spark Plug 1 each Mtrcf

1991 Mercedes-Benz 500SL Spark Plugs

Spark Plugs for Your 1991 Mercedes-Benz 500SL

NGK – G-Power Spark Plug: Single Platinum Tip Design, BKR5EGP (Part No.7090)

Champion – Platinum Power Spark Plug: Powerful Perfromance, OE Replacement, RC12PYC (Part No.3071)

NGK – Iridium IX Spark Plug: Single Iridium Fine Wire, BKR5EIX (Part No.6341)

ACDelco – Double Platinum Spark Plug (Part No.41-808)

DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, last 100K+ Miles, IQ16TT (Part No.4706)

E3 – DiamondFIRE Automotive Spark Plug: More Power, Saves Gas (Part No.E3.48)

Champion – Champion Copper Plus- Single Card – RC12YC (Part No.71-1)

Champion – Copper Plus Spark Plug RC12YC (Part No.71)

NGK – OE Series V-Power Nickel Spark Plug: V-Groove Tip Design, BKR5E (Part No.7938)

NGK – OE Series Standard Nickel Spark Plug: Conventional Tip Design, BKR5ES (Part No.2460)

Autolite – Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration (Part No.3926)

Autolite – Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life (Part No.APP3926)

DENSO – PQ16TT Platinum TT Spark Plug (Part No.4507)

Autolite Iridium – Iridium XP Finewire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP3926)

Champion – Iridium Spark Plug: Maximum Performance, OE Replacement, RC12WYPB4 (Part No.9201)

Motorcraft – SPARK PLUG (Part No.SP-424-X)

DENSO – Double Platinum Spark Plug: OE Performance, lasts 60K+ Miles, PQ16R (Part No.3005)

Bosch – Super Plus (Copper Core) Spark Plug (Part No.F1000298680BOS)

Motorcraft – Spark Plug 1 each Mtrcf (Part No.SP-424)

FAQs for 1991 Mercedes-Benz 500SL Spark Plugs

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