They use an electric power boost system so that the engine doesn't need to run for the brakes to have boost. In our 2001 Prius when you stomp on the brakes a few times you'll hear a whirring sound for about 5 seconds, that's the electric (vacuum?) power brake "recharge". Also with HSD (and similar) you aren't turning the ignition "off" because the engine-off mode is automatic and designed to operate like that, if you did manage to shut it down while driving I'm sure all sorts of things would not function.

2001 Prius Photos       2005 Prius Photos
1992 Mitsubishi Delica Diesel-WVO Hybrid Photos

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I can understand FAS on a non-hybrid, I used to do it on my 5-spd RX-7, had a mile long coast in a residential area with almost no traffic on the way home to my house. I actually didn't have power steering in that car to begin with so there was no difference. I have taken power steering out or removed the belt in most of my other cars. I feel I have more control and am more connected with the car without it. There really isn't much need for assist once the tires are moving, they turn rather easily, and if you have a little bit of strength, you can still turn it with even the slightest roll. The hard part is when you are completely stopped. Then you may want to have greater strength. The brakes worked fine, but I was only slowing slightly once and stopping once (in my yard/roundabout). I also was confident in my ability to pull on the e-brake if necessary and drop it back in gear as well. my e-brake could lock up for 'fun' (180s 360s), and I had practiced stopping the car with it before just in case of an emergency. I don't reccommend it to be done often, but if you did try it, then you will be confident in the situation should it arise. You would be better off taking the advice of shutting it down at red lights, drive-thrus, waiting on someone ... but if you are really confident, and try it when it is safe (NO traffic, pedestrians, any property around to be damaged) ... and feel it will be no problem, then go for it. If you have even the slightest doubt then don't. It is not worth risking your life or anyone elses, or even your car or anyone elses. Your insurance premium going up would outweigh any FE benefits. I know I would not be happy if someone piled into my car because they were FASing for FE and totaled my 'baby'.

As far as FAS with a Hybrid for coasting ... I know for a fact on HCH-I, it runs on 1 (one) cylinder during a coast and deceleration ... read it on the honda website last night, the HCH II shuts the valves down on all the cylinders ... so the gains will be minimal with either one. xcel is another story all together ... he is magical, and about as dedicated as they come.

It seems your family likes toyota ... try to get your dad to trade the car in on the camry hybrid. basically the same car right? Or try to get an HCH or Insight for yourself if that is feasable.