Which Spark Plugs Are Best For My Vehicle?

There are two basic types of spark plugs on the market: your basic copper-tipped plugs, which can last up to 30,000 miles and long-life platinum and iridium-tipped plugs which have a life expectancy of up to 100,000 miles. Recommended replacement intervals vary by manufacturer and should always be followed.

Spark Plug Metal Types

Copper Spark Plugs

Formulated for reliable performance in all conditions, copper plugs are known to deliver quick starts, smooth acceleration and good fuel economy for older cars, trucks and small engines.
ACDelco Professional Conventional Spark Plugs are designed for reliability and efficient performance, and are a high quality replacement ideal for many vehicles on the road today.
  • 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
Autolite Copper Core plugs are your industry standard, and are guaranteed to deliver quick starts, good fuel economy and smooth acceleration.
  • 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
  • Cold-formed steel shell precision rolled threads
  • Full copper core electrode provides better performance in all conditions


NGK Copper Spark Plugs are workhorses, and are at the heart of smooth-running engines around the world.
  • Corrugated ribs prevent flash over
  • High dielectric strength
  • Proper heat transfer
  • Greater spark and heat transfer
  • Three-step trivalent-plating process uses silver chromate and zinc for maximum corrosion resistance
  • Triple gasket-sealing process virtually eliminates gas leakage past the shell
  • 99% highly pure alumina silicate insulator enables use of longer insulator noses to reduce fouling


Platinum Spark Plugs

With a platinum tip that helps eliminate gap erosion, single platinum plugs are designed to fire more quickly and efficiently, than equivalent copper plugs to offer enhanced starting and acceleration, as well as improved fuel economy and reduced emissions.
ACDelco Professional RAPIDFIRE Single Platinum Performance Spark Plugs are manufactured to meet or exceed manufacturer specifications for fit, form, and function.
  • Solid state suppressor regulates spark energy for long electrode life
  • Innovative design protects against high combustion pressures
  • Pure copper core provides great heat transfer and helps maximize plug durability
  • Platinum center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
  • Ribless insulator helps optimize plug to boot seal


Autolite Platinum spark plugs provide a center wire platinum firing tip, which reduces gap erosion, helps prevent misfires, and offers improved performance and durability.
  • High nickel alloy side electrode maintains precise gap
  • Full platinum tip assures virtually no gap erosion
  • Necked-down center electrode fires quicker and cleaner with less voltage for easier starts, quicker acceleration, and improved fuel economy
  • Leak-proof, heat-fused resistor offers added stability
  • Yttrium-enhanced ground electrodes deliver superior heat transfer


NGK G-Power Platinum Spark Plugs are designed to meet and exceed OE specifications and designs for improved fuel efficiency, lower emissions, and quicker starts.
  • Fine platinum tip reduces voltage requirement
  • Extremely durable under high heat
  • Trivalent metal plating provides superior anti-corrosion and anti-seizing properties
  • Can provide faster starts and quicker acceleration
  • Helps maintain or improve fuel economy and reduce emissions


Double Platinum Spark Plugs

Double platinum plugs feature platinum-to-platinum firing. It’s the preferred technology for distributorless ignition system (DIS) engines, which make up the powertrain of most vehicles on the road today. Double platinum plugs provide faster starts and quicker acceleration, better fuel economy, and improved durability.
ACDelco Professional Double Platinum spark plugs are premium aftermarket plugs. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance.
  • One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal
  • Reduce radio frequency and engine interference, regulates spark plug energy, and protects against compression pressures for long life
  • Double platinum point pad on center and ground electrodes offer excellent durability and consistent voltage demands to help reduce wear on the ignition system
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance


Autolite Double Platinum spark plugs feature platinum-to-platinum firing to increase vehicle performance. Built to meet or exceed OE specifications, this spark plug provides quality technology for Distributorless Ignition Systems (DIS).
  • High nickel alloy side electrode
  • Full platinum tips
  • Necked-down center electrode
  • Full copper core center electrode
  • Virtually eliminates gap erosion, reduces misfires, and provides improved durability*
*As compared to standard plugs
NGK Double Platinum Spark Plugs

NGK Double Platinum Spark Plugs

NGK Double Platinum spark plugs offer high ignitability and longer service life. Dual platinum surfaces ensure a slow wear rate, providing stable idle, superior anti-fouling performance, improved fuel efficiency, and lower emissions.
  • Laser-welded platinum center electrode tip
  • Platinum disc welded to the back side of the ground electrode provides long life
  • Trivalent metal plating provides superior anti-corrosion and anti-seizing properties
  • Can offer faster starts and quicker acceleration
  • Improves fuel economy and lower emissions
  • OEM-approved design


Iridium Spark Plugs

Iridium spark plugs are among the most technologically advanced spark plugs available on the market today. In fact, most late-model vehicles include this type of plug from the manufacturer. The design of iridium spark plugs delivers better overall ignitability and optimum performance, including outstanding acceleration, high fuel efficiency and maximum durability.
ACDelco Professional Iridium spark plugs provide high melting points and great strength, and provide excellent wear resistance and durability.
  • Iridium offers excellent engine idle stability and smooth performance
  • Iridium allows for small, efficient electrode designs for reliable cold starting and quick acceleration
  • Iridium fine-wire electrode helps burn away carbon deposits on the tip of the plug as they form
  • One one-piece suppressor seal helps block radio frequencies that can affect vehicle electronics
  • Suppressor seal meters spark energy for long electrode life and helps prevent combustion leakage
  • As spark plugs fire at an extremely high rate, these Professional Iridium spark plugs are under constant chemical, thermal, physical, and electrical attack by corrosive gases that can reach upwards of 4,000°F


Autolite Iridium XP Enhanced Alloy Technology spark plugs are one of the brand’s most technologically advanced spark plugs ever. These spark plugs provide optimum performance.
  • Iridium-enhanced center electrode
  • Patented, platinum sidewire technology
  • 0.6-mm finewire design
  • Nickel-plated shell


NGK Iridium IX Spark Plugs are designed specifically for the performance enthusiast. These plugs offer extreme ignitability, improved throttle response, and superior anti-fouling.
  • Fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today’s high-tech, high-performance engines
  • Trivalent metal plating provides superior anti-corrosion and anti-seizing properties
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance


Spark Plug Metallurgy Comparison Chart

Spark Plug Metallurgy Comparisson Chart - Mileage

Mileage / Service Life
Precious metal electrode material provides longer life, increased durability/mileage between service intervals.
Spark Plug Metallurgy Comparisson Chart - Fuel Efficiency

Fuel Efficiency
Replacing your vehicles spark plugs with the OE Metallurgy or higher/better is important for maintaining or increasing your vehicles fuel economy.
Spark Plug Metallurgy Comparisson Chart - Fouling Resistance

Fouling Resistance
Fine wire electrodes help reduce spark plug fouling by providing a more focused, consistent spark.

Additional Resources