Higher octane needs usually result from higher compression in performance engines. This higher compression can result in the fuel igniting (in the absence of a spark from the plug) before the piston reaches TDC (well, actually the engine should fire prior to TDC. It is just firing earlier than it should in the process). Retarding the timing will do nothing to prevent pre-detonation (pinging) in that case. Also, higher octane does *not* result in more horsepower. Octane represents the resistance of the gas to detonation, the higher the octane the more resistant the fuel is to detonation. It does not have more stored energy.
-Gary Gary VanderMolen said the following on 8/17/2005 12:13 PM: > Veech wrote: > >> $3.00 + in LA, and I had to buy a car that uses premium! Wonder how >> much >> damage I'll do to run it on regular? > > > Most people don't realize that premium gas is just regular gas > with some anti-knock compounds added. Modern engines have > anti-knock sensors, so if you accidentally fill up with gas that is > lower in octane than your engine requires, the computer will > retard the timing to take care of it. You won't get all the horse- > power your engine is rated for, but there should be no damage. > > Gary VanderMolen > > >
