I'm assuming he means a pressure spike caused by knocking.

If you plot the cylinder bode pressure an engine running normally should have a nice smooth graph throughout the cycle. This is because the charge is burning and raising the pressure to produce the power.

If the charge detonates (knocking) you see some high spikes occuring on the pressure graph

 

No, not in the UK.

 

Thats right fluffy, its basically pre detonation of the fuel in the cylinder which is bad news. It can actually burn through a piston. In extreme cases it can kill an engine in seconds. Much more of an issue in a forced induction car. Spikes are bad as its a very sudden temp rise.

Ive started using Ultimate or Opti in the S2000.

MB

 

Ultimate is bloody expensive though - I paid 90.9p for it last week . I normally use Esso Super as it's much cheaper and there's an Esso garage at the end of our road