I visited my friend's cabin over the weekend and discovered that my FEH could not back up his driveway! The driveway is about 75 feet long and made of concrete with a traction surface. It's also on a 17%+ grade! The Escape made it up about halfway and then came to a dead stop; without the brake it started slipping back down the hill. With a running start it made it up about 2/3 the way and stopped. My driveway grade at home is about 13% and the Escape and Highlander both have no problem.
The Escape only runs the electric motors when the SUV is in reverse. In fact, the owners manual says it's maximum speed in reverse is 22 MPH (presumably for this reason). I had no problem driving forward up the driveway w/the Escape because the ICE assisted with power. And it was never a problem backing up it with my 3.8 L V6 Mustang either in the past.

Anyone else have experiences like this?

 

Everyone will experience the same thing you did, given the same situation. The Prius/Escape setup just works that way. It only uses the electric motor for reverse and does not use the ICE to assist at all. You just have to remember not to park that way on a hilll like that. Just back in (so you can front out) and you'll be fine.

P.S. The Civic doesn't work this way because the ICE is always on in reverse.

 

Actually, here's the real story...

The FEH can only use the electric motor(s) for reverse. This is true.

However, in EV mode ( ICE off ) you only get 15,000 watts, or about 20 horsepower to the wheels in reverse. This is because the battery holds 10,000 watts in reserve to start the engine, when called upon.

Now, if you run in reverse with the ICE on, the ICE can spin the generator, and give you much more electrical power to the wheels. Like 40,000 watts, or 53 additional horsepower.

Now, if the battery is full, and engine is on, the battery does not need to hold 10,000 watts in reserve, so 25,000 battery watts is available to the wheels.
Add this to 40,000 watts from the generator and you have 65,000 watts, or 87 horsepower to the wheels in reverse.

There will be cases where EV ( battery only) will not push you up a hill in reverse, but battery plus engine on will.

Give this a try. I suspect 87 horsepower will push you up almost any hill in reverse. It is true, you sometimes need a running start. If you chock the wheels, or start uphill from a dead stop, there is a current limiter that will cut-off the power if you are not moving.

Hope that helps, and good luck!
-John

 

Did you "floor it"? I know it sounds strange, and it feels even stranger the first few times you try it, but the ICE will come on and deliver more juice to the electric motor.

 

Randy,

If you have tried it, does the transition feel smooth in that the power comes on in a predictable manner? If one were backing up a steep hill to park, for example, and the extra power comes on at the last second, would the FEH lurch backward?

Thanks,

Roch

 

Good questions. I would think there would be no more lurch then when the ICE starts up when in Drive. However, this is not something someone comes across often ( needing full power in reverse ) so I really can't say.

Most of the time ( flat parking lots ) the 20 HP EV mode is just fine.

One time, on a steep gravel road, I needed battery + engine... but the engine was on from the start. Using the watt meter I was in the 35,ooo to 40,ooo range, so I know the engine was "helping".

 

We have noticed a similar thing when backing out of our parking space (a little pull out of a broad "C" shaped drive, backing out is a slight uphill), IF there is a lot of snow or ice. Although I would have expected the electric motor to work well in such a low-speed, high torque (is that right?) situation, sometimes it seems as if it just shuts off and there is NO power to the wheels (is that the "current limiter" at work?). I think the ICE must have been on because it was just after starting up on a cold morning.

Didn't have that problem at all with the V6! This is the only situation where the FEH seems to "underperform" the V6 in our ordinary driving. Fortunately, we have always been able to get it out; it's been a while since I've driven the FEH, so I can't remember how I did it, whether it was by "flooring it" or trying again at a slow speed.

 

Hard to say in terms of a delicate maneuver like parallel parking on a San Francisco hill, because I've never needed it in such a situation.

I did play with reverse out on the beach after hearing from somebody else on this (or another) group that the ICE will kick into assist in reverse if necessary. The power delivery did feel pretty linear though, as you push the pedal more and more. It's pretty close to being "floored" when the ICE comes on - at least in those experiments.

I think the power delivery is fairly linear and similar to switching from EV to EV + ICE in a forward drive setting. The difference is that what takes place in a pretty small range of pedal travel in forward, requires the entire range of pedal motion in reverse.... the system is just responding to your torque request based on pedal position.

I don't have any really good hills nearby, so maybe somebody else could do some testing and report back on this.

 

Hey, that's word for word what I was going to say. Honestly, that was the same point I was going to make, just a lot less technical.

Anyway, there is a way to get more power without having to floor it to get the ICE on, it's turn the climate control to a red, to get the ICE on when you don't want to just floor it. Additionally, you can use the trick to get ICE on when you need full immediate power from a dead stop ICE off situation. (Like say, if you wanted to make a left turn in a crowded city)

 

I did have the pedal to the floor and the FEH would not climb any further. It wasn't for more than a very short moment though - I was worried about the motors so I immediately applied the brakes when it stopped uphill. The ICE didn't come on at that point but it never occurred to me that I could force it on with the defogger mode on the climate control. I will try that next time I'm up that way and report back. It didn't seem like it needed much more to climb the rest of the way up. The ICE would certainly power the motors to drive the rig backwards uphill. And Ford engineers can certainly appreciate those who parallel park downhill and have to back up to get out of a stall, or pull into a steep downhill driveway and have to go in reverse to get back onto the street (without using a winch!).

Would shifting into low gear have any effect? Does the ECVT work in reverse or is it independent of the transaxle?