Well my gf has a 93 4 door civic dx. she currently gets a messy 240 miles between fill ups. i think her tank is around 8-10gallons and i thought dxs get about 30mpg in the streets, thus she should be getting AT LEAST 300. what could it be? we changed the oil and filter, air filter, and poured some injector cleaner. would replacing her fuel filter help? what else could it be? the subwoofers?? i doubt it. anyway ithas no mods except its lowered on stock 13 inch bling blings with 160ishk miles.