I also have a DOHC auto Saturn but unlike yours mine has to haul around close to 3500 pounds buying the scangauge was the best investment in FE even beating out the LRR tires. I went from 18mpg (6 mile commute and a lead foot) to an average of over 29.5 mpg before the scangauge. Now that I have a real time feedback I can see what TPS inputs result in best milage for a given speed.....this tank I'm looking at 33+ and no EOC.
Yeah, I stopped EOC, only really did it for one tank but it just didn't seem beneficial enough for me in my route to/from work to use it daily.
Basically all I've done it learn to drive differently, stiffer accell to 4th gear, then chug along at 40mph in city maintaining 4th gear in all possible circumstances, monitor the TPS and MPG as well as IAT and *Fwt and this is the result. Seems I'm getting 31.xx mixed now as opposed to 26/27, and my highway mileage is getting unreal as far as what I thought was possible.