I am writing this assuming that the Titan has
knock sensors. Does it?? It seems like now
all/almost all engines have knock sensors & it
seems like they began to be widely used at the
time that the manufacturers began getting good
power out of their engines. Now, my tuning
experience goes back to when a dual point
distributor was the hot item. Back then for
most engines to get the max performance you
would advance the ignition timing as far as
you could without causing engine damage. Is it
still that way??
I am slowly getting to the main question:
if the engines can 'comfortably' run on the
octane specified, what is the 'main' reason for
having knock sensors? Is it because they are
giving an extra margin of safety or is it that
the octane they are specifying is marginal??
I have been for years using gas with octane a
couple of pts. higher than specified to be
sure the knock sensors don't cut back on the
timing. Cutting back on the ignition timing is
definitely a performance killer, or at least
it used to be.
Does anyone know if the octane specified by
the manufaturers is marginal?

Yes the Titan does have a knock sensor..What a knock sensor does is well, like the name implies, senses engine knock..The computer in the car will constantly adjust timing to be optimal for the conditions present (ie: intake air temperature and volume, load, demand, ect)...So, when full power or alot of power is needed from the engine, it can advance the timing as far as possible until it detects detonatoin or knocking then retard it slightly..It can retard the timing for ease of startup, then when started, adjust to the "cleanest" running....So it is neccassary to a knock sensor to be there otherwise, the computer wouldn't know when to stop advancing the timing..