There are several different 2005 Honda Civic models. The DX, GX, EX, LX and VP trims are all rated at an EPA estimated 32 mpg city / 38 mpg highway. With Civic Si models, estimated mileage is 25 mpg city / 31 mpg highway. 2005 Civic Hybrids get an EPA 45 mpg city / 51 mpg highway. Civic HX Coupe drivers can expect 35 mpg in the city and 40 mpg on the highway.
Gas mileage can vary dramatically based on driving habits. Fast driving will bring your mileage down considerably, especially in the hard-revving Civic Si. On the other hand, accelerating conservatively, shifting early and maintaining even speed can bring your mileage to levels over and above the EPA estimates.
If you are seeing gas mileage very far under the provided numbers, there could be something wrong under the hood. Improper timing can result in your engine running rich or using too much fuel relative to the amount of air entering your cylinders. If you take it easy on the gas and are still achieving poor 2005 Civic fuel economy, take the car in to get checked out.
