I'll add my story here now that I'm back on the list after letting the Nut Wagon rest over the Winter.
My driving technique is low RPM (under 2000 RPM), low speed (40-45 MPH), and a lot of engine-off coasting down hills and to stops. I don't do pulse and glide on flat roads. I try not to brake or idle.
The 1991 Civic Wagon running the original 1.5L 16-valve engine, but half the rocker arms have been removed, turning it into an 8-valve engine. And I have a CRX HF transaxle that keeps RPM low. Plus a lot of little stuff that adds up. Full mod list is in my garage.
To keep my numbers accurate, I burn full tanks. And I've checked my odometer via GPS and adjust the odometer reading to reflect actual distance.
I use no MPG instrumentation. Mostly because MPGuino won't work with my TBI.
Details: Nut Wagon - 1991 Honda Civic Wagon DX Fuel Economy - EcoModder.com
1991 Honda Civic Wagon DX Gas Mileage (Nut Wagon) - EcoModder.com