So I was thinking of hydraulic power steering?
Yes. A hydraulic power steering would have a resevoir, rubber hydraulic lines, and a belt driven pump. When ecomodding vehicles, it's a common thing to swap a power steering rack for a manual one. Electric power steering would have 0 effect on your MPG's because it is not driven by the drive belt.
I still deliver pizzas in my Cobalt as well, but I used to own a 2001 Saturn SL1. I ecomodded it to get better gas mileage. The manual steering rack was my next move when it finally got killed by electrical bugs at 298K+ miles.
The first step is to look at anything run off the drive belt (which I believe is the A/C, tensioner wheel, alternator, crank, and one more I'm sure I'm missing).
If you live in an area where removing A/C is possible without being overly uncomfortable, removing the whole system not only removes it from the drive belt, but also reduces the weight (albeit very slightly, but every pound counts on these small cars).
Also, switching to lightweight pulleys reduces the amount of power required to turn them, thereby allowing your engine to run more efficiently. MRZ performance sells lightweight pulleys for our cars for the crank & alternator. Both require you to use an impact driver to remove the factory pulley & then to reinstall the lightweight ones. You will just have to remember to change the pulley out every time you replace the alternator.
Lightweight Alternator Pulley - Ecotec 2.0LNF/2.2/2.4 - 5 ribs
5 ribs - Ecotec Lightweight Crank Pulley - 2.0LNF/2.2/2.4
Also, anything you do to shave weight will also increase your milage, but not by as much as removing/improving on the drive belt system.
On my Saturn, I completely removed the back seats, passenger seat, all seat belts except the drivers, most of the trim & carpeting, and the A/C system. I was averaging almost 50 MPG with street driving & about 55 MPG highway.