JD has the best sticky on this...need to read it...my point i run 18* timing 34 total and i have ran 89,and 91,92,93 whatever and it has showed zero gains plugs all looked the same,and zero pinging...


btw i have ran 118* at the track,and my car was cooler which resuted in a little quicker times

 

I dont know why people think that putting 93 in their completey stock car will help it somehow. I run 93, but my timing went from 8* to 18*, and pings at 91.

 

I run 94 now... grr higher prices. [:@]

 

sounds like carbon build up

 

In the manual that came with the car doesnt it state to ONLY run 87 octane, nothing higher (2000 gt)

 

Who me?? I'm supercharged with an assload of other stuff done. If i ran 87 you would watch my pistons explode into tiny pieces.

 

IMHO The benefit of advancing timing is that it allows more time for a complete burn. Of course once you get the complete burn there is no benefit to advancing it more.

The 4.6 does not have a static or initiall timing like motors with a distributor so the benefit is only in keeping the computer from retarding timing when it detects detonation .

Octane allows for a slower burn and the fuel itself has resistance to getting set off by something like a hot valve, hot spark electrode etc. So in effect, the fuel prevents auto dtoantion and knocking. There is a limit to how much octane will be of benefit so basically if the motor does not knock U don't need the octane.

There is a posibility that high octane fuel is a better product and that it contains detergents etc.

Aside from that, I don't think that high octane has any more of an ability to produce power, make an engine last longer etc.