Octane. You sometimes see the word when you visit the petrol station but what does it mean? Octane ratings measure fuel's ability to resist engine knock. Engine knock is caused by fuel being ignited by something other than the spark plug. 

Normally:

  • Unlead fuel will contain 95 Octane level
  • Super Unleaded will contain 97-99 Octane

If you are using an octane grade that is too low for your vehicle, something other than the spark plug can ignite the fuel in the engine. The engine could even get hot enough where the fuel explodes by itself.

What octane does your vehicle require? Check your vehicle's owner's manual. Don't upgrade to more expensive octane (super unleaded) ratings unless your manufacturer recommends it.