I just got my 07 FEH last week, haven't even done a tank yet, and I've read some posts here, including the FEH FAQ.

I live in upcountry Maui. Generally, I'm either driving up Haleakala Highway or down Haleakala Highway. I don't understand why I have to play games with the brake pedal when I'm coasting down hill (at or above 50mph) in order to get the ICE to turn off. In most cases, once I get on the highway going downhill, it's a long 7 mile coast to the first traffic light. Why doesn't the computer figure it out itself? Eventually, at the bottom of the hill when I start to slow down, it will turn off, but it doesn't turn off like I would expect it to when just coasting downhill at speed.

My other question is a little different. The first thing I did was to replace the factory stereo with an Alpine head end unit with a full-speed ipod interface. I also replaced the factory speakers and added a 200w (50w x 4) Alpine Amp. I'm also going to add a second mono-block 220w amp for a small 10" subwoofer (I'm getting anemic Bass from my upgraded system) and I was wondering what the effect is on the hybrid charging system is by adding these 2 amps?

Thanks,
David

You must be traveling below 40 miles per hour for the ICE to shut off. It will continue to run if you are driving 40 miles per hour or faster regardless of whether you are coasting or accelerating.

Yes, but why?

-David

To avoid over spinning of MG1.

Ken@Japan

Its in other posts on this site look around for the details... essentially (I'm not sure where) but a component in the transmission will spin faster than its allowed rating.. by allowing the ICE to spin the extra RPM is burned up by the ICE and the component won't exceed its design limits.

As a matter of fact above 40MPH you'll never get the ICE to shut down no matter many brake tricks you try.

If you have the NAV you'll note that even though your ICE is on your MPG will be at MAX. The ICE is being spun around by the weight of your vehicle.... not gasoline. There is no gas flowing at those times (supposedly...I'm not sure thats confirmed) but your MPG isn't harmed much by it so just ignore the effect. Try to trust the engineers... they did a good job on this thing and had several years of looking at it. If it does something, you can pretty much be assured there is a GOOD reason it does it.

I don't have the NAV system, but thanks for the explanation.

-David

Hi David

MG1 is short for motor generator 1 and Ken is right on with his answer. There is a way around the problem and some of the advanced hypermilers have been using it for years. I recently have starting using the technique, but I would caution you on it as a new FEH owner. Here is a link where I discuss the technique in the FEH: http://www.cleanmpg.com/forums/showthread.php?t=3440

As far as adding the equipment you described for your audio system, all I can say is the power for the subwoofer for my Nav sys comes directly from the Smart Juction Box. There are shielded wires and many warning in the FEH repair manuals about interference with the PCM with such wiring and equipment. In other words, I don't think Ford techs would advise you on that addition and you may void some coverages for repairs by doing the changes by unauthorize Ford dealers.

Good luck with it!

GaryG

Thanks for the link. I'd be concerned safety wise about doing the key-off thing, but thanks for the info.

As far as the amplifiers are concerned, they, of course, will be wired properly from the fuse box with properly shielded wiring, etc, and the equipment is fused itself. I can't see how properly adding a reasonable amount of audio equipment could void the warranty.

-David

I'm not trying to pick a fight (I honesty wasn't the last time), I'm just asking a question because I DON'T know the answer.

Do we know if this saves any gas on the FEH? Some people seem (erroneously or not) to believe there is no gas flowing to the engine in such cases anyway.

The NAV goes to max during those times, however that really just indicates >60MPG. I see on my scanguage that the number is pretty high much higher than 60 which agrees with the NAV. However.... its certainly not 9999MPG which is what the scanguage reads when you are in EV mode and there is NO gas flowing.

Somewhere I thought I remember reading that the Scanguage doesn't actually measure fuel flow but instead infers it from the RPM and such.....
is it possible that the reading on the scanguage is in error because it sees an RPM and assumes there is fuel flowing and these other posts are right. Or is the above statement about the scanguage in error and the scanguage is reading correctly.

I haven't tried the key off or anything so I'm curious.

Speaking of Toyota Prius, we observe complete fuel cut during going downhill above 42 miles per hour speed.
My SuperMID M-1 milease meter shows no fuel flow on such condition.
http://www.greenhybrid.com/discuss/s...ead.php?t=3015

Prius Scanguage users also report incorrect, 200 someting, mpg numbers on the same condition.
I believe the Scangauges have such limitations.

Ken@Japan