I know that allot of you don't really understand forced induction very well, but let me see if I can put it simply. :rolleyes:

Normally the engine computer is tuned to use premium gas on a forced induction engine (Turbo, SC). This allows them to run more timing and less fuel for better power.

Most factory tuned cars are designed to limp on regular fuel even if it wants premium. This prevents bent rods and such when “Jo consumer“ decides to forget that it wants the good stuff and puts 87 in.

This is normally accomplished by a knock sensor. This is basically a little microphone that is attached to your block and listens for certain frequency noise above a certain decibel level.

When it hears knock, it retards the engine timing. Retarded timing = Less power. This can be a big loss, as allot of the time the knock sensor will pull allot of timing just to be safe.

Bottom line, low octane gas=really crappy SC performance. Also the knock sensor is hearing detonation, maybe very mild, but it is still there. If you are getting detonation, you are hurting you engine.

Use the 91+ octane and stop risking a bent rod for cents a gallon.


Sean