During my years as a driver I've coasted down hills and coasted when I needed to gradually slow down, but only after slobbering over ecomodder.com did I understand Pulse & Glide. This weekend I borrowed my father-in-law's car to run some errands with my wife and I used that chance to try my luck with P&G.
We took a highway with a flat 5km stretch which is more or less straight. There was a crosswind, strong at times. The speed limit is 70 km/h (I try not to go over the limit more than 10 km/h and am regarded by Warsaw drivers as dangerously slow). I accelerated to 80 km/h and started coasting. When my speed fell to 70 I accelerated again to 80 and so on.
The car doesn't have anything like a Scangauge and Dad would probably like to keep it that way, so the only measure of efficiency I had was how far I coasted when slowing from 80 to 70 km/h. This distance was between 150 and 200 meters, the average around 180m. I don't know if that's good or bad, though I've read that some ecomodder members can coast for hundreds of meters. Once I tried to turn the engine off (but keep the other systems on), but my wife was not amused. I know the car can do better, but Dad isn't open to any kind of modding. Maybe when we get our own car in which I change few things and he sees that my FE is 20% better, then maybe he'll let me try a grill block, airdam or narrower tires on his car. But wheelskirts and mirror chopping will still be out of the question
Here's the car's specs: Peugeot 206 5-door, 1.4l 75hp, weight about 950kg plus 2 people, tires 175/65R14 (I say they're too wide - the Opel Corsa C is about the same size and has narrower 155/70R13's). The only eco thing I got away with is pumping up the tires - they are at 40 psi while the door sticker says 30-35.