Spark Plugs

  • ACDelco® - GM Original Equipment™ Iridium Spark Plug
    3
    # sp217451
    GM Original Equipment™ Iridium Spark Plug by ACDelco®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $5.05 - $10.28
  • ACDelco® - Professional™ Rapidfire Conventional Spark Plug
    3
    # sp48807
    Professional™ Rapidfire Conventional Spark Plug by ACDelco®. Designed for today’s most popular autos, as well as several marine applications, ACDelco’s Rapidfire® Platinum Spark Plugs fit engines using conventional plugs, as well...
    Ribless insulator that improves the plug-to-boot sealTapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage
    $2.78 - $3.52
  • Motorcraft® - Platinum Spark Plug
    2
    # sp6037
    Platinum Spark Plug by Motorcraft®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or...
    Direct OEM replacementRecommended by Ford Motor Company
    $1.72 - $9.17
  • Denso® - Original U-Groove Spark Plug
    1
    # sp94899
    Original U-Groove Spark Plug by Denso®. Denso's patented U-Groove spark plug enables complete combustion by allowing the spark to fill the gap created by the U shape. The ball of fire created in the U-Groove develops a larger and hotter...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $1.21 - $6.06
  • Champion® - Copper Plus Spark Plug
    0
    # sp205164
    Copper Plus Spark Plug by Champion®. Built with nickel alloy center and ground electrodes, these spark plugs provide extra durability for long-lasting service life, while the extrusion of copper into the core of their center electrode...
    Dependable and durableBuilt to ISO and SAE standards for proven performance
    $0.35 - $28.03
  • NGK® - Standard Nickel Spark Plug
    1
    # sp207674
    Standard Nickel Spark Plug by NGK®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $1.46 - $15.81
  • Motorcraft® - Finewire Platinum Spark Plug
    4
    # sp6038
    Finewire Platinum Spark Plug by Motorcraft®. If you need to replace your worn-out spark plugs, Motorcraft is the way to go. Engineered specifically for your vehicle, their high melting point provides outstanding resistance to erosion...
    Direct OEM replacementRecommended by Ford Motor Company
    $2.73 - $14.18
  • ACDelco® - GM Original Equipment™ Spark Plugs
    2
    # sp217452
    GM Original Equipment™ Spark Plugs by ACDelco®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $1.45 - $14.64
  • Mopar® - Iridium Spark Plug
    1
    # sp123040
    Iridium Spark Plug by Mopar®. Replace your worn out spark plugs with these top-grade replacement spark plugs and get your vehicle back on the road. Designed with expert craftsmanship and extreme attention to detail, they provide the...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $2.93 - $42.36
  • Bosch® - OE Specialty Nickel Spark Plug
    1
    # sp101655
    OE Specialty Nickel Spark Plug by Bosch®. Replace your worn out spark plugs with Bosch spark plugs and experience miles of worry-free driving. OE Specialty Spark Plugs ensure safe and reliable performance, same as your OE plugs, so you...
    Designed to meet or exceed OE specificationsMatch the fit, form, and function of the OE design
    $1.35 - $7.67
  • ACDelco® - GM Original Equipment™ Double Platinum Spark Plug
    1
    # sp217450
    GM Original Equipment™ Double Platinum Spark Plug by ACDelco®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $5.36
  • ACDelco® - Professional™ Spark Plug
    2
    # sp14259
    Professional™ Spark Plug by ACDelco®. Designed for today’s most popular autos, as well as several marine applications, ACDelco’s Rapidfire® Platinum Spark Plugs fit engines using conventional plugs, as well as newer vehicles...
    Ribless insulator that improves the plug-to-boot sealTapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage
    $1.28 - $14.45
  • Motorcraft® - Iridium Spark Plug
    1
    # sp6039
    Iridium Spark Plug by Motorcraft®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or...
    Direct OEM replacementRecommended by Ford Motor Company
    $3.51 - $11.82
  • Motorcraft® - Copper Spark Plug
    1
    # sp6040
    Copper Spark Plug by Motorcraft®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or...
    Direct OEM replacementRecommended by Ford Motor Company
    $0.53 - $8.56
  • United Motor Products® - Ignition Tune-Up Kit
    0
    # sp229441
    Ignition Tune-Up Kit by United Motor Products®. Keep your pride and joy operating as it should with this top-notch part from United Motors Products. It’s made using the finest materials and advanced manufacturing equipment to...
    Excellent replacement for your worn out factory partWill help make your vehicle running as good as new
    $20.25 - $71.53
  • ACDelco® - Professional™ Double Platinum Spark Plug
    1
    # sp104626
    Professional™ Double Platinum Spark Plug by ACDelco®. Premium aftermarket plugs, and a high quality replacement ideal for many vehicles on the road today. With a copper core and double platinum pads on the center electrode, these...
    Ribless insulator that improves the plug-to-boot sealTapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage
    $4.99 - $13.82
  • ACDelco® - Professional™ Iridium Spark Plug
    0
    # sp104627
    Professional™ Iridium Spark Plug by ACDelco®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function...
    Ribless insulator that improves the plug-to-boot sealTapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage
    $5.61 - $13.73
  • Bosch® - Super Plus™ Spark Plug
    1
    # sp5796
    Super Plus™ Spark Plug by Bosch®. Replace your worn out spark plugs with Bosch spark plugs and experience miles of worry-free driving. OE Specialty Spark Plugs ensure safe and reliable performance, same as your OE plugs, so you can...
    Designed to meet or exceed OE specificationsMatch the fit, form, and function of the OE design
    $0.91 - $24.88
  • ACDelco® - Professional™ Platinum Spark Plug
    0
    # sp179696
    Professional™ Platinum Spark Plug by ACDelco®. Premium aftermarket plugs, and a high quality replacement ideal for many vehicles on the road today. With a copper core and double platinum pads on the center electrode, these plugs are...
    Ribless insulator that improves the plug-to-boot sealTapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage
    $5.12 - $8.67
  • Motorcraft® - Spark Plug
    0
    # sp136977
    Spark Plug by Motorcraft®. Is your vehicle hard to start? Does it miss under load and idle rough? Is your gas mileage not what it used to be? Your ignition system may need repair, but before you waste your time and gas running out to...
    OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price
    $1.30 - $13.27
  • Champion® - Industrial Spark Plugs
    0
    # sp226828
    Industrial Spark Plugs by Champion®. Champion industrial and agricultural spark plugs are backed by global engineering from Federal-Mogul. Precious metals, FISS and Hot Lock designs allow us to provide a plug that Withstands today's...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $2.54 - $10.70
  • Motorcraft® - Nickel Spark Plug
    0
    # sp6036
    Nickel Spark Plug by Motorcraft®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $0.53 - $6.27
  • Champion® - Nickel Spark Plug
    0
    # sp196881
    Nickel Spark Plug by Champion®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or even...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $1.61 - $2.03
  • Genuine® - Spark Plug
    0
    # sp15115
    Spark Plug by Genuine®. If your engine ignition parts is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On CARiD you'll find...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $6.87 - $108.82
  • Brisk® - Super™ Copper Spark Plug
    0
    # sp194729
    Super™ Copper Spark Plug by Brisk®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $3.60 - $11.70
  • Beru® - Spark Plug
    0
    # sp186653
    Spark Plug by Beru®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or even better...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $4.77 - $37.81
  • Crown® - Ignition Tune-Up Kit
    0
    # sp16037
    Ignition Tune-Up Kit by Crown®. Crown Automotive is just the ticket if you want to get the most out of your vehicle as well as revel in a more exciting driving experience. You will surely get a real bang for the buck!
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $34.43 - $112.91
  • ACDelco® - Specialty™ Spark Plug
    0
    # sp27254
    Specialty™ Spark Plug by ACDelco®. Designed for today’s most popular autos, as well as several marine applications, ACDelco’s Performance Platinum Spark Plugs fit engines using conventional plugs, as well as newer vehicles...
    Ribless insulator that improves the plug-to-boot seal.Tapered center wire electrode with a platinum pad reduces the firing diameter and helps improve the firing efficiency by concentrating and directing energy needed to fire the plug with less voltage.
    $1.65 - $3.06
  • Denso® - Iridium Spark Plug
    1
    # sp173546
    Iridium Spark Plug by Denso®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or even...
    Manufactured to restore your vehicle’s ignition systemDesigned with your specific vehicle in mind
    $2.51 - $17.35
  • Denso® - Spark Plug
    0
    # sp172452
    Spark Plug by Denso®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or even better...
    Fully Projected Insulator Reduces Carbon FoulingMachine Rolled Threads Prevent Seizing or Cross Threading During Installation and Removal
    $0.53 - $12.08




For a gasoline powered internal combustion engine to run it must have the proper mixture of air and fuel, compression, and a well-timed spark. Fuel mixes with air in a carburetor, or in the intake manifold or port after the fuel injector on electronic fuel injected engines, and is then drawn into the cylinder through the intake valve when the piston descends on the intake stroke. The piston compresses the air/fuel mixture into a small, dense volume when it rises in the cylinder on the compression stroke. High voltage produced by the ignition coil is sent to the spark plug, which creates a spark igniting the air/fuel mixture, generating combustion pressure that forces the piston down on the power stroke. On a 4-cycle engine the spark plugs fire 300-400 times per minute at idle and 1000-1200 times per minute at cruising speed, and they do this for many thousands of miles. With that kind of firing frequency, it’s no surprise that even the best plugs wear out eventually, and when they do you can count on our replacement spark plugs to restore performance.

A typical spark plug consists of a copper core center electrode and metal terminal inside a ceramic insulator that is encased in a steel shell. The terminal connects the spark plug to the ignition system. The center electrode has a nickel alloy, platinum, iridium or other precious metal firing tip. Resistor spark plugs include a resistor with the center electrode to prevent electrical interference that can adversely affect radio reception and vehicle computer controls. The steel shell is threaded for secure fitment in the cylinder head and to provide a good ground and effective heat transfer from the plug to the cylinder head. The side electrode, or ground strap electrode, is made of high nickel steel that’s welded to the steel shell. Double platinum spark plugs have a platinum disc welded to the side electrode.

The ignition coil turns the 12 volts from the battery into 15,000-40,000 volts. The coil is directly connected to the spark plug on COP (Coil On Plug) ignition systems, connected via spark plug wire on DIS (Distributorless Ignition Systems), and via spark plug wire and distributor on breaker point and distributor-type electronic ignition systems. When the breaker points, ignition module, or ECU (Engine Control Unit) triggers the coil, the high voltage transmitted through the spark plug arcs across the gap from the center electrode to the side electrode and ignites the air/fuel mixture. The pressure created by combustion of the air/fuel mixture pushes the piston downward, providing the force that turns the crankshaft. While all spark plugs function the same way and have similar construction, they are tailored to their applications and ignition systems with different electrodes, thread sizes, seat type, heat ranges, and reach.

There are four common spark plug thread diameter x thread pitch combinations: M10 x 1.0, M12 x 1.25, M14 x 1.25, and M18 x 1.5. Spark plugs can have a flat seat that uses a gasket to seal the plug to the combustion chamber or a tapered seat where the spark plug shell forms the seal. A spark plug’s heat range is its ability to transfer heat from the combustion chamber to the cylinder head. On a “hot” spark plug, much of the ceramic insulator will be exposed to the combustion chamber, so it retains heat and burns off deposits. In contrast, very little of the ceramic insulator is exposed on a “cold” plug, enabling it to transfer heat better and run cooler. A plug that runs too hot for the application can cause pre-ignition and knock, and one that runs too cold can result in carbon buildup and misfire. Cold plugs are generally used on modified high-performance and racing engines. Spark plug reach is the distance the plug projects into the combustion chamber. The plug must project far enough for good combustion without getting too hot or hitting the piston and should not be so shallow that it’s shrouded, resulting in poor combustion.

Copper core spark plugs with nickel alloy firing tips, commonly called copper/nickel plugs, are usually specified for breaker point and some electronic distributor ignition systems because the softer nickel alloy erodes faster and won’t last as long as platinum or iridium when used on modern DIS and COP ignition systems. However, because they run cooler, copper/nickel plugs are used on some late-model performance engines. The firing tips on platinum plugs are much harder than copper/nickel plugs; they will retain their sharp edges and gap dimensions much longer than copper/nickel plugs, so you can count on many more miles of good performance. Platinum plugs also operate at a higher temperature, which resists carbon buildup. Some platinum plugs have fine-wire tips, which need less voltage to fire and increase firing efficiency.

Double platinum plugs were designed for DIS ignition systems. In a DIS system each coil supplies voltage to the spark plugs in two cylinders on every revolution of the crankshaft, with one spark plug firing in the cylinder on the compression stroke and the other in the opposite cylinder in the firing order that is on the exhaust stroke. Because the spark in the cylinder on the exhaust stroke has no effect on engine operation, this is commonly called a “waste spark” ignition system. A double platinum plug, with a platinum disc welded to the side electrode, is needed in this system because, while the spark plug in the cylinder on the compression stroke fires in the conventional manner, from the center to the side electrode, the spark in the cylinder on the exhaust stroke jumps from the side electrode to the center electrode. If spark plugs without platinum side electrodes are used in a DIS, the side electrode will wear prematurely.

Iridium is even harder than platinum, and iridium plugs last even longer than platinum, and now there are ruthenium-tipped plugs that are harder still. The hardness of precious metal tipped plugs is emphasized by vehicle makers and spark plug manufacturers because hardness provides durability. Harder electrodes will maintain their sharp edges and the plug gap longer, for good spark and consistent performance over many thousands of miles and extended change intervals. Along with precious metal and fine wire firing tips, some spark plug manufacturers form U-shaped or V-shaped channels in the side electrode or shorten or alter the shape of the side electrode to reduce the quenching effect that can be caused by conventional electrodes and cause incomplete combustion.

Every time a spark plug fires, a small amount of electrode material is lost, eventually resulting in rounded electrodes and wider gaps, which require more voltage to fire, and could cause misfire. This occurs on all spark plugs regardless of the type of electrode, it just takes materials like platinum and iridium longer to wear. In addition to normal wear, spark plugs are also subject to engine conditions like a rich air/fuel mixture, worn piston rings or valve seals that can cause fuel or oil fouling or excessive deposits, and detonation or pre-ignition damage caused by incorrect ignition timing, use of fuel with too low an octane, lean air/fuel mixture, defective EGR (Exhaust Gas Recirculation) system, or excessive carbon deposits in the combustion chamber. Symptoms of worn, fouled, or damaged plugs include misfire, rough idle, hard starting, poor acceleration and reduced fuel mileage. Spark plugs should be replaced when recommended by the vehicle manufacturer or when there are symptoms of poor performance. Upon removal, plugs should be examined for evidence of the engine conditions described above.

The engine design dictates spark plug features like diameter, thread pitch and seat, but other features like heat range can be changed. However, unless the engine has been significantly altered and you are an experienced tuner, when replacing spark plugs you should stay with the type of spark plug recommended by the vehicle manufacturer. We make it easy for you to select the plugs that meet or exceed your engine’s requirements. Just plug in your year, make, model, and engine size in the fields at the top of this page and you’ll instantly be shown a selection of spark plugs from the top brands, and each one will deliver the performance, fuel economy, and durability you’re looking for at an affordable price. Besides spark plugs, we offer spark plug tubes and seals for engines that require them, as well as tune-up kits for select vehicles that include plugs, distributor cap and rotor, plug wires, filters, and more.

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  • When Is It Time To Replace My Spark Plugs?
    July 04, 2018
    When Is It Time To Replace My Spark Plugs?
    Spark plugs are a key ingredient of gasoline engines when it comes to serving up a dish of solid power. More specifically, they conduct electricity derived from the...

Spark Plugs Reviews

167 reviews
5 of 5
Mopar Sp143877AB. Iridium Spark Plugs
Mopar® SP143877AB - Iridium Spark Plug
My 014 charger RT is running like new after 100k strongly recommend them!
Posted by Benjamin / May 26, 20202014 Dodge Charger
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