What size ar original honda civic wheels for a 96 5 door?

the aftermarket alloys need changing and i want to bring it back to original spec there ar 13" wheels on it now.whats the original factory size .its a 1996 5 door 1.4 civic.ps has anyone any idea of what milage i should be gettin at the moment after a full service im gettin around 160miles to a full thank (around 45 liters) while Driving around a town .is this average or is she thirsty lol