Spark Plug Guidelines for Honda Engines

04- 07- 2024
By Shawn Ortiz
Acura, Automotive Repair, Car Troubleshooting, Denso Spark Plugs, Engine Maintenance, Engine Performance, Honda, Honda Engines Spark Plugs, Ignition System, NGK Spark Plugs, Resistor Spark Plugs, Spark Plug Guidelines, Vehicle Maintenance,

Importance of Resistor Spark Plugs

For optimal performance and to prevent electrical interference with on-board electronics like the ECU, it's crucial to use resistor spark plugs in all Honda engines. Non-resistor plugs can cause significant issues, particularly with on-board datalogging systems.

Recommended Spark Plug Brands

We highly recommend using NGK or Denso spark plugs for Honda engines. Other brands such as Bosch or Autolite have been known to cause ignition misfires. This is because Honda engines are designed for a specific flame front development and travel, which NGK and Denso plugs are tailored to. Using other brands can lead to misfires, detonation, and poor fuel economy.

Why Resistor Spark Plugs?

According to NGK, resistor spark plugs are essential for vehicles with on-board computer systems as they minimize electromagnetic interference. Non-resistor plugs can cause undesirable effects such as erratic idle, high-rpm misfire, engine run-on, power drop off, and abnormal combustion.

Selecting the Right Heat Range

The heat range of a spark plug affects combustion temperatures:

  • For higher combustion temperatures: Use a hotter plug (lower number).
  • For lower combustion temperatures: Use a colder plug (higher number).

For performance engines with higher compression or forced induction, we recommend using a colder plug for every additional 100 horsepower. For example, if your engine's stock output is 150hp and you've increased it to 250hp, opt for a plug that is one step colder than the factory recommendation.

Adjusting Spark Plug Gap

The spark plug gap influences the plug's tip temperature and the voltage needed to ignite the air/fuel mixture. Higher compression ratios or boost pressure generally require a smaller gap to ensure proper ignition. While the factory Honda ignition system is usually sufficient, those experiencing ignition issues with a small gap may benefit from a higher output aftermarket ignition coil. This allows for a larger spark plug gap while maintaining adequate voltage to ignite the mixture.

For more detailed information, refer to the guidelines provided by NGK.