Re: 87 or 93 gas
From personal experience, I can say that I get my best gas mileage with my tuner set to 91 octane Performance tune. 87S and 93R don't do as well. Prior to getting a tuner I got my best mpg using 87 octane.
The higher the octane number the more resistant the gasoline is to combustion and therefore less prone to pre-ignition. Higher octane is generally only necessary for:
A) High compression/forced induction engines, or
B) Engines with stock internals that have the timing advanced a great deal over stock, such as you would get with a custom dyno tune, or a Bama tune etc.
The short answer is 87 without a tuner, 91-93 with a tuner.
YMMV... but this is what I experienced myself.
01 V6 5 spd
Windstar upper, shorty headers, high-flow catted X, American Thunder catback, SCT Tuner, ASP 25% UDP, FRPP T-Lok