M177-M178 HKS Spark Plug set
ECU Reflash required? NO
HKS Spark Plugs to suit M177-M178 4.0 litre BiTurbo engines.
A noticeable difference in performance over other brands.
- Smoother acceleration
- More Power
- More reliable
Choose from standard heat range (Suggested for up to stage 2 vehicles) or one heat range colder (stage 2+ and more)
About Spark Plug Heat Range:
have a longer insulator that prevents heat transfer into the water jackets. It keeps more heat in the tip of the spark plug, which helps burn off combustion chamber deposits. But if there's too much retained heat, the engine will experience preignition.
have a shorter insulator and retains less heat at the tip end are only required when higher boost levels cause increased cylinder head temperatures. If the plug is too "hot" pre ignition may occur. —but if it's too cold, deposits accumulate and eventually the plug will foul.
Included in the box: