Mods to increase highway mpg?

[civic94]

I have a 97 geo prizm, same as the corolla. It has the 1.6L, 3 speed auto WITHOUT overdrive, Without a locking torque converter. its rated at 22 city /27 highway.

I want to make it better drink less gas on the highway, Im going to take a road trip soon. So far it has 44 psi tires all around, and an intake. other than that its all stock.

It spins at 3000 rpm at 60 mph, 4000 at 70, 5000 at 80. i know, its not a great car for highway, with only 3 gears and no locking torque converter. I have thought of selling it for a better mpg car, but the car is mostly driven in the city, and not too often.

Is there any other way i can increase the mpg through mods? I usually drive the limit on the highway, and at 60 mph i can attain about 32 mpg through scanguage.