Using this information below you can quickly understand, and select a spark plug more ideal for your situation.

​

This is not a plug reading guide! This is a plug buying guide, first of its kind.

 

Factors effecting spark plugs 

• Fuel - Petrol or E85

• Desired Boost pressure / BSFC

• Target Power (KW) / Per Cylinder

• Compression Ratio

• Air Fuel Ratio / Lambda / BSFC

​

General Rules

• A cold plug will fowl, a hot plug will destroy an engine. 

• The more power increases, the colder the spark plug.

• The higher the rpm, the colder the spark plug.

• The leaner the Lambda, the colder the spark plug.

• Iron heads need colder plugs than aluminium heads.

• Track cars need significantly colder spark plugs.

• Most importantly, Never buy from non-specialists or non-genuine sources.

 

Remember

1. If you're unsure, check plugs offten.

2. At 450°C the spark plug reaches its self cleaning temperature.

3. Knock is a symptom of failing spark plugs.

4. A failed spark plug is likley to destroy an engine.

   1. Detonation - Spark plug turns into glow plug​.

   2. Ceramic failure - Spark plug ceramic falls into the cylinder. 

​​

 

Ultimatley spark plug selection is purely dependant on cylinder temperature. Exhaust gas temperatures indicate how high they might be. 

​

​

We made this guide for Aus Dyno ❤️ We're not responsible for you're choices you make when you're modifying you're car. This is a guide not an instruction. Please don't use this calculator!