How to make my 2001 Honda Civic LX more gas reliable?

I'm not the type to spend money on speed upgrades. I would like to range somewhere between 36 to 40 city/Highway but if there's a way to get more, I'd like to know. What parts can I buy and what can I do to make my car get the best of gas mileages?

Change how you drive, buy a fuel consumption guage.

Oh, I should probably also mention it's a manual transmission. That mag help out a lot in getting the best answer.

You can lose 50 pounds that would help. Get plastic windows. Strip out whole interior leaving just the driver seat. Always drive with 1 or 2 gallons of gas so you would save like 30 pounds in gasoline.