Does the FEH use an extra motor to power the rear wheels in the 4WD model?

 

No.

"Escape comes standard with front-wheel drive. Escape’s available Intelligent all-wheel-drive (AWD) system was tuned with an emphasis toward driving performance while offering confident all-weather driving. Using a preemptive slip strategy, the system continuously monitors vehicle speed, throttle input and steering angle to seamlessly deliver torque to the appropriate wheel even before wheel slippage occurs. The system also helps eliminate torque steer and helps balance the vehicle when cornering. Intelligent AWD uses an active on-demand coupler to allocate a precise amount of torque from front to rear or side to side, with up to 100 percent of the torque going to either axle. "

ref:Ford Press Release

 

The Toyota Highlander Hybrid AWD and Lexus RX400 AWD use this type of setup in which a second electric motor is utilized to power the rear wheels only. The second rear electric motor is rated at 50kw (68HP).

This is from an autochannel review of the Toyota Highlander Hybrid: http://www.theautochannel.com/news/2...14/051904.html

• #%&!! traction control … Unfortunately, there is no way to disable the standard electronic traction control. When photographing the Highlander for this story, we found a road down to the beach. Our goal was to put a sand dune behind the truck to make a nice photo. Even though our Highlander Hybrid featured four-wheel drive (the internal combustion engine and transmission/motor combo drives the front wheels while another electric motor powers the rear wheels), in very shallow sand while still on the access road to the beach, the Highlander stranded itself immediately. With the wheels spinning in the sand, the traction control thought we were “slipping” on dangerous ice or snow and decided for us that we should just be parked. Without being able to spin the wheels to gain some traction, we could not extricate ourselves from the sand, and needed several beachgoers to push us out. For this otherwise capable SUV to essentially strand itself seemed entirely out of character. And very frustrating to the driver. It’s a helpless feeling to know the vehicle could easily drive itself out of the situation if it would only let itself. While Toyota corrected this oversight on gasoline powered Highlanders for 2008, on 08 Highlander Hybrids, there is still no “off” switch for the traction control.

I remember reading an "expert" from Consumer Report on their forums stating we have overheated the electric motor on this vehicle. I copied this from the CR forum site: ... From our experience with the Lexus 400h and Highlander hybrid, there is no traction problem in snowy conditions. Tecnically, when the rear mounted electric motor overheats in continious use, such as crossing a sand dune, it'll shut off. Ford, mind ... [ 7265.5]

Hope this helps.

 

Thanks. I was looking at the Highlander and the Escape about two years ago. Now that I am getting serious I got the rear wheel motor on the wrong car. Hey, I'm 67.

 

And that would be why Ford doesn't have it. They tested it extensively, and came up with several problems. Just as a fun fact, the Toyota Highlander (and RX400H) system was initially designed by Ford, and was bought by Toyota when Ford scrapped it due to said problems when they were working on a Hybrid Explorer. (Back before there was an Escape and the big movement into Hybrids.) Toyota tinkered with the system and made whatever changes they made, but they did use Ford technology as a starting place.

When Ford again got serious about Hybrids, they went with the intelligent version of the more standard system, having still not solved the problems of leaving an owner stranded under certain circumstances.

 

The FEH & MMH use the same 4WD system, basically, as did, does, the old Ford Aerostar. In "auto" position the system monitors for torque induced wheelspin/slip and engages the 4WD coupling.

The Aerostar included an actual transfer/diff'l case and that allowed it to DRIVE both front and rear simultaneously, 30/70 normally and then 50/50 with wheelspin/slip.

The FEH/MMH on the other hand just uses a simple clutch coupling to drive the rear wheels when conditions warrant.

Amd therein lies the problem.

The FEH/MMH are FWD, sideways mounted engines.

FWD vehicles MUST NOT BE ALLOWED, EVER, to lose roadbed traction due to engine torque. The HARZARDS are simply too great. Loss of roadbed traction at the front often, TOO OFTEN, leads to loss of directional control and an accident.

Were I to purchase an FEH/MMH I would probably remove a front drive halfshaft and wire 12 volts permanently to the rear drive clutch. Torque induced wheelspin/slip at the rear leaves you, STILL, with directional, stearing, control.

Toyota has just announce a TC, Traction Control, sub-mode, available ONLY on the RWD or R/AWD vehicles. The new sub-mode will allow some level of wheelspin/slip in the event that is what is needed to get unstuck or up and moving initially.

FWD vehicles are PATENTLY UNSAFE in adverse roadbed, ice and packed snow, conditions.

 

In your opinion....

Lets face facts. The US moved from PREDOMINANTLY RWD systems to FWD systems years ago. If they were PATENTLY UNSAFE... would you please explain the lack of data showing a HUGE DEATH jump from the move? MOST OF THE VEHICLES on the roads today are FWD... and the accident rate has gone DOWN... I'm not saying FWD made it go down... but it doesn't seem to have made it go UP.

Yeah... torque steer can get you into problems... If you behave yourself, you are fine. Having the engine weight OVER the drive wheels can often GET YOU OUT OF problems too.

I've got to say.. I'd rather drive my old ZX2 on snowy packed roads than a RWD pickup any day of the week. Been driving FWD for 22 years.... I've NEVER encountered any problem where I've had the **** thing loose traction in the front with torque steer. I live in MI... I lived in Vermont for 3 years and the upper penninsula for 5 years... been on ice MANY TIMES. Perhaps its just not driving like an idiot on ice? I've used my front wheel drive to PULL me out of slides when I was hitting the brakes many times... thats not torque steer slides mind you and I'd argue most times you slide on ice its when you are hitting the brakes... not when you are GENTLY accelerating...and thats the KEY... GENTLY!

I've actually never been in an accident on ice or snow, but driven on it many times. Seen plenty of pickup trucks in the ditch during those years.... lots of 4WD SUV's as well...

Only accident I've had was on dry pavement when I was an idiot and looked away from the road.

I wouldn't call it definitive but check out

http://www.cartalk.com/content/colum.../March/10.html

Even the car talk boys say its not true...

Basically its mostly an overreaction and a load of mis information.

 

This sounds more like the older AWD system of the Escape, 2001-2007. The newer system is electronically controlled, not a simple "mechanical slip" system. The Ford writings indicate that it can go into AWD even before slippage.

 

"Ford writings..."

Yes, and just how much electronics knowhow or implementation does it take to predict the future, that somewhere, in the nearby future, wheelspin/slip will develop unless corrective measures are implemented.

But yes.

Cadillac came to the realization, finally, that they were shooting themselves in the FOOT via sales of a FWD vehicle with an extremely high torque Northstar V8 engine. That's a BAD way to be losing customers.

So, what did Cadillac do..?

Well, first they adopted an over-running clutch within the transaxle so that engine lagging torque, engine compression torque, could not be "reflected" to the front drive wheels as BRAKING. Engine braking that often resulted in the loss of ABS functionality.

Then next they began dethrottling that high HP/torque Northstar engine, for which they were famous, at "launch" time so the driver could not inadvertently lose directional control via the application of too much torque.

But then they kept losing customers, the HARD way, to the GRIM REAPER.

So Cadillac decided to abandon the FWD market altogether.

Wise, WISE choice.

But in Ford's favor almost all manufacturers of FWD and F/AWD vehicles are now automatically dethrottling the engine (ICE and Electrics for the FEH/MMH) when entering a tight turn, accelerating into a tight turn. That action both eliminates instances of high levels of torque stear and significantly reduces accidents due to understearing/plowing.

"Nanny mode."

Ford, in a strange way, does actually try to predict the future. If the FEH/MMH is driven into an area of sub-freezing weather then the level of regenerative braking is significantly REDUCED. This is done to protect the driver against the potential for loss of control due to FWD "engine" braking should an ice patch be encountered. They also disable regenerative braking anything you are using the brakes and ABS activates.

Many manufacturers of F/AWD vehicles are now automatically engaging the rear drive system at "launch", most especially with a "leadfoot" launch, or HARD accleration into a turn, a TIGHT turn.

One does wonder just how long the driveline would hold together driving FAST in a TIGHT circle.

But I suppose the firmware design types have provided for that by automaically dropping out the rear driveline coupling after, say, 20 seconds of continous engagement but with no wheelspin/slip.

That's probably what the "ford writings" are referring too, very clever wording, that.

 

According to the Ford documentation, AWD vehicles engage the rear wheels as the vehicle comes out of a turn, to provide traction. Can't say anthing about the technical details, but that is what they say.

The regen braking is also suspended if the ABS activates.

BTW, I had a CR-V formerly, AWD, which I had in all sorts of nasty weather, and had no problems. AWD, of course, does not help when slowing, only when getting started (and occasionally as needed when the front wheels slip).

I'm afraid I haven't read of any disasters involving the Grim Reaper traced to AWD and front transaxles. Cadillac prefers RWD because it handles better.