stick with regular unleaded. dont waste your money with the premium, your engine was meant to run on 87. Short ram intakes, I'm not positive since I've never used on, but I know for sure that they increase low end torque.

This is my setup right now and I'm averaging about 400+ mpg city and 550+ mpg hwy.

-I have a cold air setup from http://www.acautotechnic.com. if your interested Not the best but not the worst either.
-header
-still using the stock catalytic (test show its only about 1-2 horse power lost from a high flow aftermarket, not test pipe its actually -1 hp.)
-and a full cat back exhuast.
-NGK v-power plugs, tried iridiums already
-Nology wires
-and castroil high milage oil, 5w-30

I've been using this for the past year. I've never missed resetting my tripmeter. with gas prices so high I cant afford to.

hope this will help any