What misconception? I said it could be used for HP in a sports car and then when I was talking about the VW. I described a very similiar idea to get better gas mileage.... In their case they are using an undersized diesel, but same idea... create denser air to get more HP using less fuel in a smaller engine....

I don't see the misconception about superchargers and turbos there? I said the same thing with fewer words, but the same thing.

You could probably tweak an FEH in similar ways to run better with denser air conditions but it wasn't designed that way so when it sees colder denser air... it doesn't run optimally, it wasnt' optimized for those conditions....

 

Another common misconception...

A higher octane fuel results in a slower moving flame front, slower, more even burning rate of the A/F mixture.

The timing issue has to do with the lower octane fuel burn having a sudden, quick, PEAK burn and therefore the timing must be retarded to delay this "peak" well beyond the TDC point.

The knock/ping that results from the use of low octane fuel is caused by the piston not being able to move down, away, as fast as the flame front expands. Look at a sine curve, the distance the piston travels versus degrees of rotation is lowest at TDC. Basically the same as the knock/ping you can get with any fuel by "lugging" the engine.

With the quick, peak, burn rate of the lower octane fuel, even with the ignition delayed, the piston cannot move down/away as fast as the flame front expands, so some energy is always lost, even absent reaching the point of the severe mechanical stress that you hear as knock/ping.

Higher octane equals higher FE because less energy is "wasted".

 

"...it wasn't designed that way..."

Sorry, that's EXACTLY the way it was designed.

There are two MOST "optimal" levels of operation of the ICE, be it Otto, Atkinson, or even Miller Cycle. WOT, wherein pumping losses are minimized, and the lowest possible engine RPM (lowest frictional losses) wherein enough, only enough, HP is produced to move the vehicle along at the desired constant speed.

And no, you wouldn't have to "tweak" the FEH/MMH engines at all, they already are, that's what the non-conventional CVT is all about. To drive my RX300 along at 65MPH with its FIXED overdrive ratio the engine MUST turn at 2400RPM. With your hybrid CVT it is only necessary for the "engine" to turn at whatever RPM will produce the engergy level needed.

Same with the other end of the "spectrum". When you need to accelerate the ICE can go WOT and the RPM can quickly climb to its most effiicient HP/torque RPM due to the infinite gear ratios available within the range of the CVT.

Put premium fuel in my RX300, the engine must still turn 2400 RPMs at 65MPH, put premium fuel in my Prius or your FEH, the engine RPM can drop to whatever level is needed.

 

If the FEH is already designed to get the best gas mileage when the air is cold and dense you'll need to tell mine. For some reason it thinks it should get 4-5 MPG LESS than it did during the summer on the freeway. That has nothing to do with battery efficiency since the battery isn't being used very much at freeway speed and the motor and generator will work better cold (as far as electrical resistance in the windings is concerned). Once friction has warmed up all the oil, bearings most of the friction differences should go away.... we are pretty much left with engine efficiency in cold air and pushing the vehichle through cold dense air. The latter wouldn't seem to account for a 4-5MPG loss.

 

"..nothing to do with battery efficiency since the battery isn't being used very much at freeway speed...."

I wish, sincerely, that were a TRUE statement.

On a ~150 freeway drive our Prius will use the electrics as "boost" any time there is a need to regain the target cruise control speed. Because there is little, if any, opportunity to recharge the hybrid battery via regenerative braking the battery charge will evenually decline to the point wherein the ICE "MUST" be used to recharge it, bring it back up to about a 90% charge level.

On our 150 mile freeway drive it seems to do this at least 5 times.

I have been tempted to find a way to modify the system so the electric "boost" does not happen as I'd be more satisfied with better Freeway FE than the quicker acceleration. I sincerely suspect if the electrics could somehow be eliminated from freeway activity the FE would increase to equal or betetr than that of a standard, equivalent, Otto engine car.

And keep in mind that along with the need to heat the cabin and the catalyst there is the issue of the patent. The more often your climate is close to freezing the less regenerative effect you will have and it will be necesssary to use the ICE to make up for the loss. Also remember that winter days are shorter and that means using the lights and headlights mor eof the time than in summer. I've been a little puzzled about why Ford doesn't use the more highly efficient HID lighs for that very reason. Or even moreso why owners aren't converting to HIDs and LEDs where ever possible.

It is entirely possible that the FEH/MMH climate control design will operate the A/C compressor even though cooling is NOT required. Lots of modern day systems do this on the theory that it can be used for dehumidification and thereby help to prevent window and windshield fogging. Prior to discovering that my RX had a C-best option to accomplish that very thing I would open the signal wire from the climate control ECU to the engine ECU that signaled the need for operating the A/C.

 

From my experience watching the NAV it appears the FEH handles freeway driving quite differently than the Prius. There appears to be no slow decline on our battery meter over long miles. Sometimes when climing a hill on cruise you might see a few seconds of battery use... but on the far side if the hill you see energy flow back into the battery. However the battery really appears to be used fairly little in flat terrain at freeway speeds.

 

I've not much experience with the FEH other than a test drive or two and a short trip in a friend's FEH. But since my interest in freeway FE is fairly high I did simulate the typical experience I have with the Prius by disengaging cruise and then "resuming" cruise after the speed dropped 5-7 MPH several times. It was my impression that the level of electrics used in that instance, to regain the cruise target, was about the same as the Prius.

But certainly not enough to dispute your understanding.

 

Willard,

Things have changed over the past 40 years and your mixing the thinking of the past on today technology. I'm 52 yrs old and can see where you come from.

Todays cars can go faster and more efficient because of design. The FEH is as fast as the V6 Escape, but gets much better FE. The Prius was not designed like the FEH, so why compare the two. The FEH battery, the motors and the engine are not in the same class as the Prius. The problems you see in the Prius with highway driving, are not the same as the FEH.

Garyg

 

"..mixing the thinking of the past on today technology...."

How so, can you give me an example?

And sorry, I have it on very good authority that the FEH/MMH hybrid drive system, base design, is licensed from Toyota, and not only that, it is my understanding that the FEH uses the same control firmware as the Prius with relatively minor tweaks here and there.

Ford chose to use the Prius hybrid drive design rather than the RX/HL because with those Toyota had decided that since the Prius hybrid design could not be upscaled and still remain fuel efficient they went for HP/torque, 0-60 times.

Luckily Ford did not follow Toyota's "lead" and so the FEH/MMH is quite fuel efficient in comparison to the RX/HL.

My understanding is that Ford could not make the FEH "work" without infringing on a substantial number of the early Toyota patents and rather than license the individual patents "piecemeal" they licensed the entire "package".

"...The FEH is as fast as the V6 Escape..."

Since I rather doubt that this statement relates to roadspeed maybe you will be interested in the following...

Did you know that the new LS460 gets 30MPH just cruising along at freeway speeds? Engine turns only 1400 RPM. And the GS450h goes from 0-60 in.....

 

I thought knock/ping was the result of the uneven burning of the fuel, which caused uneven pressure on the top of the piston. The uneven pressure is basically one side being pushed down harder/faster than the other. With that, the piston "tilts" causing the sound. ????