Rep Power: 0

2004 Honda Civic 2 doors. 1.7 L engine
I rebuilt the engine and now I get 18 mpg. My drive is mainly on the highway
the car has power and no any other symptoms whatsoever, no smoke , overheating etc but it sucks gas
what things should I look for in order please
Thanks

 
Rep Power: 222

What did you replace/take apart?
No check engine light? No codes?
Timing correct?

 
Rep Power: 512

pop the hood with the engine running. See if you can smell fuel.

 
Rep Power: 367

Past due o2 sensor

 
Rep Power: 0

I want to thank you all
My daughter drives the car and I think AC is on all the time with full blast.
I’ll fill the car and drive on the highway and see the actual mpg. I used to get 34 mpg easily before I rebuilt the engine
Here’re the things I did when I rebuilt the engine in place , wasn’t a full rebuilt
- Machined head gasket area and replaced the gasket
- valve adjustment
​​​- Honed the cylinders and Replaced the Rings
- replaced all the bearings over the crankshaft
​​​​​​-replaced the cover gasket
Timing belt was replaced one year before the work I did so I didn’t replace it again

sadly I forgot to clean the fuel injectors
Thanks

 
Rep Power: 512

How old is your daughter? Could be a case of lead foot. lol

That'll kill mileage for sure though. Then again, when I had a turbo on my 2002 civic, the worst mileage I got was about 15mpg, and I was flooring it everywhere with the A/C full blast (ballpark calculated by killing a quarter tank in 50 miles). Still might wanna consider other factors since my turbo civic and lead foot made marginally worse fuel economy than what you're seeing on this rebuild.

 
Rep Power: 367

a day of autoX where we floor it only in 1--2 gears brought MPG down to 7-8 MPG.

 
Rep Power: 222

My guess would be lead foot as well

 
Rep Power: 367

other than that, the o2 sensor

 
Rep Power: 224

I'll state the obvious, who's calculating MPG? If it's her, does she know how to properly? Tank must be filled to the same level (within reason) every time to be accurate.