Ok, I will admit to using the e-brake during an auto-stop to avoid the loss of brake pressure from causing an engine restart. I never do this above 15 mph, and I use it in stop-and-go conditions only, and typically on mild downhill grades when it is most useful.

I also never rely on the main brake's mechanical backup (by allowing brake pressure to drop during an FAS) because it takes a lot of leg strength (which means I admit to trying it enough times to decide it was a stupid thing to do).

If you haven't tried it yet then find a safe spot at say around 15 mph, and lightly pump the brake pedal with the engine off, the brake pressure will fade after a few pumps, and you can see just how much leg strength you need to get the car to stop. If you don't want to do this then take my word for it, it takes a lot of leg strength to stop the car. My take is you would never want to rely on that pitiful backup in a panic stop situation.

Cruising at freeway speeds during an FAS without brake pressure would be playing Russian Roulette in my opinion. Sooner or later you would lose.

That is probably a good safety tip, if you touch the brake pedal at all during an FAS, it is time to turn the key and start the engine for a few seconds to restore that brake pressure.

I have experimented with it and takes only a second or two of the engine running to fully restore brake pressure. And only a few pumps of the brake pedal (two or three) will fully lose brake pressure.

I live on a hill and used to coast out my driveway and start the engine at the bottom of the hill when I first needed brake pressure. I have rethought that little stupidity as a result of this thread and promise to start the engine at the beginning and FAS to the bottom with full brake pressure. :-)

Technical details: It is the act of the brake pedal moving in that uses up pressure, holding the pedal with a constant pressure does not lose brake pressure (other than what you used to get there in the first place). So you can come to a full stop safely on stored pressure but be careful to engage the brake pedal and hold it relatively constant, the key is never go up, only down, there is even enough stored pressure for a single full panic stop. So if you want to play Russian Roulette, at least now you know how it works.

I think what we have here is a feature request for hybrids, just like the A/C compressor can work without the main engine on the 2006 HCH, it would be a nice if the brakes could too. :-) Then we could FAS to our hearts content and not have to worry about brake pressure.

Since it is a safety issue it might even be a bit of a priority for car manufacturers, of course we would have to publically admit to doing foolish things like cruising down the freeway at 60+ mph with the engine (and hence the power brake pump) off. Personally I think this is a good argument against FAS at freeway speeds, or any speed over about 20 mph. Which is probably why Honda doesn't auto-stop over that speed anyway.

I remain a fan of FAS when sitting at a stoplight with a cold engine however. :-)