[savefuel]

I average about 15-20% EOC with my VW GOLF TDI 1.9. P&G mainly depends on road topography, weather conditions, time of day (day/night) and mandatory speed reductions (approaching a speed limit).
The key is to manage gliding in neutral, gliding with gear engaged but foot off the accelerator or engine off coasting (EOC). This is a constant decision making progress with adds to the fun of hypermiling! Driving a turbo, I allow the engine to stabilize on idle RPM prior shutting it off. The engine reengagement is being done by applying a suitable gear while the car is still coasting and release the clutch. I only do P&G on slight downhills with speed variations of less than 15 mph (eg. 60 to 48, acc. to 60 ...). Of course You get the best results on daily commutes!
A nicely maintained 1.9 VW GOLF TDI (vehicle weighs in at 2900 lbs with driver) delivers 50/55 mpg w/o P&G at 50/55 mph.
With P&G the mileage can be boosted by another 10/15 mpg (also depending on traffic and topography).
And we're talking of US-Gallons here, of course.
(Increase the USG mileage by 20% to get IMPG mileage)