GM's factory spark plugs are typically ACDelco, GM's in-house brand, though some engines or markets may use NGK or Denso as OE substitutes depending on model and year.
GM's OE spark plug landscape
Most GM vehicles come with spark plugs sourced through ACDelco, the GM-approved Original Equipment brand. The exact choice can vary by engine family, production region, and supplier agreements. Modern GM engines often use iridium or platinum plugs for longer life, while older designs may still use copper-core plugs.
- ACDelco is the primary Original Equipment spark plug brand used by GM for the majority of its vehicles.
- In certain engines, regions, or model years, GM-approved substitutes from NGK or Denso may be specified as OE.
- Electrode materials commonly seen in GM plugs include platinum and iridium for longevity, with copper-core variants appearing on older designs.
- The exact spark plug specification (heat range, thread size, and gap) is defined by GM's service information and the vehicle’s engine family.
When replacing spark plugs, you should reference the owner's manual, the GM service information, or the official GM parts catalog to confirm the correct part number and plug type for your vehicle.
How to identify and order the right plug
To ensure you install the correct plug, follow GM's official guidance and use the engine code or VIN to cross-check part numbers. The process typically involves confirming the engine family and checking the recommended heat range and electrode type in the GM catalogs.
- Identify your GM vehicle's engine family using the VIN or owner's manual.
- Check the GM Parts Catalog or the vehicle’s service bulletin for the recommended spark plug heat range and material (iridium/platinum/copper).
- Match the exact GM part number or use GM-approved cross-reference with NGK or Denso equivalents if allowed for your engine.
- Install with the correct torque and gap specifications, or have a professional service technician perform the replacement.
Note that some markets outside North America may have different supplier arrangements. Always confirm with a dealer or your region’s GM service site to ensure the plug you buy is approved for your specific vehicle.
Regional variations
Global supplier assignments
GM's global operations occasionally adapt the OE spark plug supplier by region, due to supply chain agreements, manufacturing plants, and engine supply needs. In practice, North American GM cars are more likely to spec ACDelco plugs, while some international models might reference NGK or Denso as OE for particular engines or years.
- North America: Predominantly ACDelco OE plugs for most models.
- Other regions: Some engines may list NGK or Denso as OE on the GM service information for specific engines or years.
Always verify the exact part number in the GM Parts Catalog or with a GM dealer for your region and vehicle.
Summary
GM primarily uses ACDelco spark plugs as the factory OE for most of its vehicles, but certain engines and regional programs may specify NGK or Denso as OE substitutes. Always verify the correct plug by consulting the owner's manual, GM’s official service information, or the dealer’s parts catalog to ensure proper heat range, material, and fit for your GM vehicle.