I am looking for someone who can tell me how to engine brake this car. I do a lot of mountain driving and when descending you need to put the car in a low gear to slow the car and prevent brakes from over heating and failure. I recently descended pikes peak in Colorado and was stopped at the check point for over heated brakes (over 300 degrees). At that temp the rotors will warp and the breaks will fail. I just purchased this vehicle and cannot find any documentation on this. According to the manual D is hybrid mode and L is drive. In the other hybrids there is a B for engine braking.

 

L will get you engine braking and you can use that gear for any speed. If the battery becomes overcharged, the engine will just burn off the excess.

This has been discussed in the past, maybe if you search for "mountain".

 

All engine braking is in "L" during deceleration. The engine RPM will go high but there is no fuel being burned in the '09 and '10 FEH. You can play around with regen in "D" with slight brake pedal pressure without using the brake pads to slow you down but your battery will get full and stop regen and start using 100% pads. You can try using the electric A/C compressor in Max A/C or defrost in the '10 FEH to use some of the SoC of the battery while it's being charged by regen.

I guess the key is to use as much energy going down big mountains so the battery does not get fully charged which will stop regen in the FEH and start using 100% pads. There is just not enough engine braking from this little engine to slow you down on a big mountain with this heavy vehicle. Remember, the '10 FEH uses cabin air to cool the battery and you can over heat the battery too much and it will stop regen also. This means you need to keep the cabin as cold as possible while charging and discharging the battery.

GaryG

 

When the battery is fully charged going downhill, doesn't regen continue with the ICE being spun up to high rpm's by the motor? I thought the purpose of the ICE revving up was to burn off the power from the regenerative braking.

 

Your right, but the problem is the ICE being spun up is not enough engine braking to slow you down and you have to use the brake pads in addition. By adding regen with MG2 you use less pads and reduce rotor heat which is Mountainman's problem going down that big mountain. The '10 electric compressor most likely uses more energy than we think and allows more regen and less pads and rotor heat than the older FEH.

GaryG

 

is the 09 air cooled also?

 

The '09 and earlier FEH does not use the cabin air for cooling the battery. They have an Aux A/C that works off the engine A/C compressor and outside air. So yes, the '09 and all older FEH are air cooled but from a different system. I'm now learning the old system is more fuel efficient than trying to cool the battery with cabin A/C that runs on an electric A/C compressor. My '09 FEH keeps the battery cooler without running my cabin A/C, and the battery performs at its peak performance. It has been in the 90s F here and I'm holding a record 61mpg tank at just under 1/2 of the tank. I should get 820 miles on 13.6 gallons of E10 gas.

GaryG

 

Pikes Peak is a hard one. But luckily there is only one place in the world like this, and I don't think you will be doing it every day.

Pikes Peak is both VERY steep for sustained distances, and has VERY SLOW speed limits, like 10-15 MPH.

Going that slow, brake pads are really your only option.
SO.... stop once or twice on the way down, and let them cool for 10-15 minutes if you are worried. 99% sure you'd be OK. I don't know where you got the 300 degrees number, as that is very, very cold. "Hot" means close to glowing red. Your brakes are over 300 degrees every time you stop at a stoplight.

You need to be going faster than 25 MPH for the engine brake to work effectively. So on most PAVED mountain roads, you will be just fine with the car in L position. Going slower than 20-25 MPH the L gear position is pretty useless.

Don't feel bad. Pike's Peak is about as extreeme as it gets.
The rest of Colorado will be a piece of cake.
( I live part time in Colorado. )
-John

 

Thanks for the good post. You are right L will slightly reduce your speed the same as letting off the accelerator and coasting. This of course is NOT engine braking. I can coast in this car down hills at 50 MPH in L. I do engine braking on all of the mountain passes I drive. Correction, not in this car.

I have a call into Ford on this issue. I will post what they say as soon as I get a responce.

 

I wonder how much engine braking one would get from a standard (gas only) I4 Escape. Is this an issue where the vehicle is just too heavy to effectively be braked by the I4engine? Also, what is the theoretical affect of the Atkins cycle with respect to engine braking?