Yeah we have some hills here that are something like that. Works well for the DFCO in my Mom's Mazda on the rare occasion that I have to drive it. I'll be damned if a car 100lbs heavier than my old 6-speed Focus with a 300cc larger motor and with a slushbox trans can't get a full 2mpg better on any of my commute routes than that Focus. My own vehicles now are crappy gliders though so it'd be just as well if we had some flat roads going on here.
'67 Mustang - out of commission after an accident
'00 Echo - DD
'11 Kia Rio - Wife's DD
'09 Harley Nightster - 48mpg and 1/4 miles in the 12's
I just drove cross-country from CA to FL and back - 7238 miles at 44.7 mpg in my Scion xB. There were three memorable legs on the trip. I averaged over 75 mpg for 40 miles from Truckee CA to Reno NV. #2 was 59.0 mpg over 165 miles from Gallup NM to Tuba City AZ, on a perfect road - long glides down mesas, and no traffic, so I could coast down to 40 mph on the 65 mph highway. #3 was 58 mpg over 40 miles, from Alexander Summit to Ely NV.
My technique may be improving, too. I averaged 51.5 mpg over the last 1213 miles from Gallup NM to the Bay Area. Not bad for a car that's only rated 28 mpg for its '08 EPA combined mileage estimate.