rotarykid said:
And on PS & PB , PS is 99 % disengaged above parking lot speeds...
I strongly disagree... with the engine off, the steering is VERY HEAVY... not at all like steering a car with manual steering, and most definitely not the same as when your car is running and you're driving above parking lot speed. (This is my experience from trying it out in both my MkIV Jetta 5sp, and my B5 W8 6sp.)
Try it in a vacant lot... even over 40 mph, the effect is dramatic. In an emergency maneuver, I've no doubt that the car will not behave in the manner that the driver both expects and requires - it simply will not respond as quickly.
As to legality... hybrids do it so it must be OK? I don't follow that logic... Hybrids are engineered to operate in respect of all other rules of the road, even when the ICE is shut down (electric power steering, for example). It's simply not the same thing. In many States, just coasting in neutral is illegal, let alone actually shutting off the engine.
http://www.cleanmpg.com/forums/showthread.php?t=3361
As to my own hypermiling techniques... the most important thing happens before you even get in the car - Route Planning. Choose the optimal route for your combination of priorities (fuel efficiency, travel time & distance, accessibility... whatever). Consider traffic volume (esp at various times of day), speed limits, road topography, construction, etc. Plan ahead and link trips together. I never "go grocery shopping", I always "stop at the store on the way home".
In the car, the most significant factor is observation - really pay attention to how (and why) you're using the right pedal, and evaluate every opportunity to see if you really need to be on the gas, or if you could just coast for those 100' or whatever instead.
Some specific things:
- if you know the light is changing to red, get off the gas immediately and coast in gear as much as possible... brake early if you can, and try to keep the vehicle rolling until the light changes.
- similar for stop signs... if there is a line of cars ahead of you, slow down further back so you can time it that you just roll to the line and don't have to stop-and-go as each car proceeds through.
- ease off the gas on downhills; you won't lose much (if any) speed, and if you get back on the gas while you've still got momentum from the hill ends, you'll get back to cruising speed with little effort
- slow down;
I've only become really disciplined with these things in the last couple of months, and I've seen a measurable benefit (~4 to 5mpg). If you want extreme numbers, you have to do extreme behaviour... something I'm not prepared to do, principally for the gross inconvenience to myself, but also to others on the road.