advance timing today what octane should i run?

I get along fine with 14 degrees timing running 89. Just put alittle in your car and listen for pinging. If you get some lower timing or up octane till your happy.

i have my timing set to 14 and i'm running 87 (mid grade for us).

i was told by my mechanic to run the premium, 91, but i put 87 in and no pinging at all.

If one runs more octane than needed, performance goes down and emissions go up.

If one has to up the octane to accomodate more static timing advance, then IMHO one should remove some timing rather than upping the octane. The gains are often simply not worth it when talking about the small octane increments found in pump gas.

Also, one can lose power before the onset of detonation - just another reason to not run on the ragged edge of pinging.

Good luck.