It could be due to the different customer model of the two manufacturers.

Ford customers want things to last a long time, and get all upset if they have to be repaired very often. Price and reliability sells the car. Speed and performance are of course desired, but secondary.

Porsche customers want things to go fast, and don't particularly care if they have to be repaired periodically. For the price that Porsche gets for one of those units, they can well afford a warranty repair or two. The speed/performance sells the car. Reliability is secondary. Price almost doesn't matter.

 

Yes GPSman1 has shown you can coast down the
Rockie Mts with full engine power, interstate road speed 60mph+ and have fuel cut at the same time for a long distance or until you hit the gas pedal. One has to manipulate the "joy-stick shift from L after the RPM spike" to do this.

 

My experience - - MMH - - 11,500 miles:

I have no problem consistently achieving 30 MPH in EV before the ICE cuts in. And for some unknown reason there have been times when I've been able to run short distances (1/4 to 1/2 mile) on level ground at speeds as high as 37 MPH in EV. Of course, on a downgrade - even a very moderate one - you can always get up to 40 MPH in EV before the ICE cuts in.

 

The official word from Ford on the 40 MPH EV limit is:

"To meet standards for noise, harshness, and vibration."

While they have made improvements to the ICE start while rolling, in their opinion, and by industry standards, the jurk or lurch "Harshness" when kicking the ICE on at speeds over 40 MPH was unacceptable, and did not meet industry standards.

Remember, all three parts are always connected, at all speeds when you have an eCVT.
Does the Porshe have an eCVT? There is no "neutral" or traditional clutch with an eCVT.

The traction motor speed is always in a fixed ratio to wheel speed.
In EV the ICE is stationary. This makes the generator speed fixed to wheel speed also.

When you transition from EV to ICE on mode, you must do the following in a fraction of a second:

A) Keep the Traction Motor speed constant with zero net change in torque
B) Slow down the generator by applying battery power and making resistive torque
C) Speed up the ICE from a dead stop with generator torque to over 1000 RPM
D) Slow down the generator by approx. 3600 RPM
E) Add fuel and spark to the ICE and have the ICE make torque
F) Have the generator reduce torque

All in 0.4 seconds, and without creating any jolt to the wheels which are connected to the eCVT the whole time??? It's amazing to me it works as-is!

So while EV is possible at any speed ( and I have been able to DRIVE, ie. PROPEL the car with battery only at 70 MPH when on a down-grade... ) the whole start-stop process for the ICE was deemed "unacceptible" from a shock, harshness, and vibration standpoint.

The ICE can, and does, often spin without fuel when you are "coasting" at high speed.
Although, not as readily as the Honda's, which cut fuel every time you lift your right foot. This is really "EV mode" since the car is not using and fuel, and the ICE is not doing any work. -John

 

I've hit 35+ mph many times

 

Huh? The Honda IMA system never shuts down the engine, except when stopped. Honda is not a "dual mode" hybrid, so there is no EV mode.

I hadn't even thought that the IMA could spin the engine without gas, which the Ford and Toyota system can do.

 

He didn't say anything about the engine shutting down--just going into fuel cut mode. I can get my HCH into fuel cut mode instantly at any speed, even while going up hill (of course you are going to lose speed fast up hill) just by adjusting my gas pedal pressure. I've gotten over 2,000mpg on the HCH (0.3L/100km) using fuel cut in the mountains

I find the fuel cut to be a pain in the MMH. I've successfully done it 3-4 times coming down I-70 into Denver, but it seems like the stars have to be in some sort of alignment for it to happen. My criteria for fuel cut is a readout of 9999mpg on the Scan Gauge with the ICE still spinning.

 

To get fuel cut on command, coast in L gear until you see 9999 MPG.
Then shift back into D and you will stay in fuel cut for the entire hill.
Shift to N and you will burn fuel at an idle pace, about 200 MPG.
That's how my 2005 works.

stevedebi,

The Honda Insight, the only Honda I own shuts off the engine completely and coasts engine off at 22 MPH and under with the manual transmission in neutral. You cannot accelerate in EV mode, this is true. The CVT Insight only shuts off the engine at 5-6 MPH and under, and you cannot accelerate in EV mode.

With a "hack" you can accelerate an Insight in "simulated" EV mode.
You trick the car while in fuel cut, and then you can drive off battery power with the tiny 3 cyl engine still spinning. It only takes an estimated 1 HP to spin the engine. The rest of the 13 HP motor can propel the car. Which is plenty. 5 or 6 HP drives the Escape on level ground. But it requires $750 of parts, and a day of labor splicing wires.
See: MIMA or Manual IMA.

 

ok, now THAT is an answer ! Thank you.

I had a feeling it was capable of more, but didnt know the reason why as everybody has seen pure EV cars do more than 40mph. It makes sense and the solution just screams series hybrid instead of parallel.

Speaking of, do you think there will be an increase or transition to more series hybrids like the chevy volt ?

 

Not sure where you got the info about the FEH's battery output, but suspect that this has been confused with the traction motor's POTENTIAL output of 70 KW, or about 94 HP. The FEH actually limits it to only 22 HP, from about 16 KW battery output, which would be it's proper rating. It would be a real road rocket with the motor putting out its full HP along with the the ICE's 133!

The HiHy has a combined motor potential of over 220 HP, but the battery limits it to 45 KW - 60 HP - for a peak power of 268 HP with the 208 HP ICE. The Cayenne, like the HiHy, apparently can sustain highway speeds with the ICE off on mild downhill grades. If it's like the HiHY, only a fraction of full traction battery output can be tapped in less than full throttle situations - not enough to sustain level highway speeds.

Pete