I started with 87, then after a year or so switched to 92, it seem to me that it took a few tank fulls to get adjusted, like being harder to start, havin to warm up to stay running, but after the 3 or 4 tank, ran better than ever, is this normal when switching octanes, will this also occur if I go back to the 87?

 

You need to reset your computer when you change octane ratings like this or it will try to burn the 92 the same way it burned the 87.

Your computer just takes awhile to learn to burn the 92 properly.

On the other hand, if you don't have Super Chip or a 4.2L, it's a bad idea to run 92 octane. The 9.0:1 compression ratio of the 4.6 will not burn it properly and you should stick to either 87 or 89.

 

The higher octanes are ment for higher compression engines, so there is no need to spend the extra money for 92.

 

Here in Austin, we don't have to burn reformulated gas. But, the
higher octane stuff has MTBE in it. You can actually smell that crap
compared to unformulated gasoline. Needless to say, higher
compression cars like Corvettes & BMW's would probably run
better (& definetely cleaner) on the 87. You'd give up a few h.p.
but my point is all computers today adjust to the fuel in the tank.

It is silly to run anything but 87 in a Ford truck that calls for 87.