I just picked up a cherry 06 FEH(4000 miles on it) to replace my 35,000 mile 05 FEH.

The new one came with the factory NAV which my 05 did not have. I will soon be replacing the awful factory NAV with the same wonderful in-dash Eclipse unit I had in my 05. In the mean time however, I have been playing with the fuel mileage & hybrid graphics screens that I never had before.

I have noticed occasionally that the vehicle when under light acceleration shows it is only being powered by the gas engine & receiving no boost/help whatever from the Hybrid battery pack. Why would this ever be the case?? It seems to me that the gas engine should ALWAYS be receiving as least a small boost from the Hybrid electric system to increase the gas mileage.

~John

 

Someone yesterday posted a great PDF that might explain this (certainly far better than I ever could, as I only vaguely understand it myself)....

{wandering off in another tab to find the thread}

Here you go...

 

At some points in the torque curve its simply more effient to drive the wheels directly than to drive the generator with the ICE and then use the current generated by the generator to drive the wheels. At constant load the current will mostly be comming from the generator, if it wasn't the battery would drain quickly.

Its best to think about it as the battery is there for acceleration, and is recharged by regen. Yes I know gary and others use EV mode alot, but not when they are driving down the highway or at constant speed for long distances.... the battery doesn't last long enough.

At constant speed the current is still coming from the ICE by way of the turning generator, that puts a certain amount of load on the ICE. The wheels put another load... the computer balances this load and finds the most efficient way to drive the wheels... at some speeds and load conditions, that means the electric motors are not involved

To WAY oversimplfy it... electric motors tend to be really good at low speed torque ICE's tend to be better at high speed torque. So when you first start moving its more efficient to put mostly electrical motor work into it but as you get faster it starts to be more efficient to do the work with the ICE. There are other points in the curve where this is true and the electric motor might not be used.

 

John, my suggestion to you is to take advantage of learning how the FEH works with the navi energy screen before taking it out. Just learning how the HV battery charges and discharges is a lot to understand.

First of all, set your SG to gauges and include "LOAD" as a gauge to monitor. After the FEH is warmed up, you will only see "ASSIST" after you exceed 99% load on the SG. At 99% load on the ICE, you are basicly at wide open throttle (WOT) which is the max torque the ICE will provide at that RPM. This is the point Ford determined you need electric motor assist for additional torque and acceleration. This is also the point you see the Charge/Assist gauge needle on the dash move into the "ASSIST" area. Using "ASSIST" will give you bad gas mileage most of the time if you don't know when to use it, such as making a traffic light etc.. Use ASSIST with the electric motors only when you need to if you want to improve mileage.

GaryG

 

Gary - your understanding of the "load" feature is incomplete.

The "load" expressed as a percentage is "the amount of available power from the ICE being used at the present RPM".

The RPM in the FEH with a CVT can be held at any RPM at any time by the motor/generator, and hence, the "LOAD" feature does not work the same way in the FEH as it would in any non-hybrid car. The ScanGauge was not made for this vehicle. While most features do work as expected, the LOAD feature does not work as you might guess.

The "load" reaches "99%" quite frequenty which is mis-leading you. That does NOT mean your ICE is maxed out on power and "needing" a boost from the battery pack. Most of the time, your ICE is not close to wide open throttle. A better setting is MAP. Any MAP less than 14.7 and you are not at wide open throttle.

Battery boost happens almost every time you accelerate from slow speed, and the ICE is maybe at quarter throttle... at most!

-J

 

John, if you don't understand engine load, don't blame me or the Scangauge. My SG works perfect for my FEH, and I think you have the load percentage backwards IMO.

GaryG

 

I have a Scan Gauge. I have a Nav/Energy screen.
I have used the SG in two 2005 FWD and in one 2006 FWD.
Assist happens at any RPM and under any load.
99% load occurs at any RPM and at less than WOT, as confirmed by MAP being less than maximum at the same time. 99% load generally occurs during acceleration, or ascending a steep grade. 99% load generally occurs when MAP is above 80%, but frequently less than 100%, which would truly be "Wide Open Throttle".

The below is almost entirely false.