Stock 4 door Corolla sedan. 7AFE engine. When I bought it last year, I got 34mpg. After mods, I got 37mpg on the first tank, then 41mpg on a 400 mile trip. Recently got over 50mpg both ways on a road trip.
Side mirror delete (only one mirror required in Montana, using the interior one), mudflap delete, stuffed the antenna into the driprail, taped off seams in front, LRR tires, Scangauge.
Wheel covers, grille block, rear skirts, belly pan on at least the front, maybe lower it (would like to find some good coilovers, not overpriced), pull the rear seat out, block heater.