Eco mode vs normal mode, pros and cons

[MeeLee]

I've driven roughly 25k miles on my 2nd hand FFH in the past 6 months, and while I primarily used the ECO settings to drive around, I now slowly have come around and will try to tell you why the eco mode can actually be harmful to your car; and why I think no one who cares about his FFH/FFE should be driving in ECO mode!
Although, eco mode is better in some sense (like better low speed MPG), in the long run, Eco mode wears out battery pack quicker, and shortens engine life.
Especially the battery is my concern, seeing that most people who had their FFH for a long time, report about 170k miles before needing to replace the pack.

 

This is my own perspective on the eco-mode on my 2019 FFH:

 

Pros using Eco mode:

- Less abrupt acceleration from a stop (in normal mode throttle is too sensitive at <15MPH, and car jolts forward too much)

- Battery charges almost to full, resulting in a longer electric range.

- Higher MPG in slow (<35-40MPH) areas

- More gentle ride

 

Cons using Eco mode:

- More aggressive charging, introduces:
 -- a higher engine load,
 -- a higher engine RPM for accelerating,
 -- Higher engine wear,

 -- A more sluggish acceleration (forcing the driver to press the pedal deeper, in order to keep up with traffic)

 -- a higher battery wear (anytime a battery is charged more rapidly, the battery will wear out faster).

- The electric motor uses more battery during acceleration (usually until about 30MPH), because it's the only thing that propels the vehicle (until the gasoline takes over).
  I believe gasoline Engine and electric motor should always be used in tandem during the acceleration phase, even in Eco mode. Even if this means that the engine will run at very low RPM, and electric motor at very low kW.
  The main form of propulsion from a stop, should always be the gasoline engine, to have as much of the MPG converted into motion, during acceleration.

- The electric motor is not really used in conjunction with the gasoline engine during acceleration, unless either the throttle is pressed down hard (fast acceleration), or unless the battery pack is fully charged or overcharged (after long regenerative braking, or long highway rides). The electric motor should not be used for propulsion, unless it is to aid the gasoline engine for faster acceleration. The electric motor should always aid the gasoline engine in acceleration, because it is a way to lighten the load on the engine, allowing it to advance the timing a bit more, and allowing it to more efficiently use each power stroke.

 

The biggest cons using ECO only mode, are that both engine and battery longevity are at stake, due to the nature of the ECO programming.
The electric motor hardly ever lowers the gasoline engine load during acceleration, but instead adds load, by switching to aggressively charge the battery (I presume robbing the engine of ~40HP).
This both adds to the engine load, RPM and thus also wear, and also lowers battery life (as with regular mode, the battery gets charged up at a much lower charging rate, presumably ~20HP? of charge speed?).

^^ This is in my opinion the main reason why you should rarely ever use ECO mode, and drive in normal mode instead! ^^

 

Now, I understand that there are some who don't care about their engine or battery life, because they're leasing the car, or because they will purchase another vehicle long before any of those two are worn out.
But for those who want to keep their FFH (and FFE) until the end, the statement should remain true.

 

Normal mode also has it's quirks.

What would have been ideal, is that normal mode acceleration would happen only when pressing the throttle down hard (for fast acceleration),
Say, you're at an intersection and want to quickly cross, before traffic hits. In this case, you want your car to respond jumpy. Not when you want to depart from a red light, but are behind a slower vehicle, and have to feather the throttle, not to cause an accident hitting the car in front of you. The throttle response is too abrupt from a stop in normal mode.
During normal acceleration (that first 10-15MPH) would have been better if it had more of the throttle response/feel and acceleration of the ECO mode. Meaning, less jumpy, while using a combination of engine and motor.
Then from 20-45MPH acceleration, stay on normal mode (where the engine isn't charging the battery, and where the electric motor can both be switched to aid the engine acceleration when needed, or start charging the battery at a slow pace, when reaching the desired cruising speed). 

Eco mode seems to charge the battery at the max the electric motor/generator can handle, unless the throttle is pressed deep, when it switches over from generator to motor, to aid the engine..
Or, switch to normal mode, and the generator switches between the ?20?HP charging, zero charging, or aid the motor.

It would be better that this charging power could be adjusted depending on the power needed for acceleration instead.
It's really not that hard, as all it takes is adjusting the coil voltage on the stator, to create a weaker electromagnetic field, resulting in a weaker charging current. There are an infinite amount of potential charging currents possible between zero and max.
 

Currently in normal mode, the gas engine is more jumpy to turn on at acceleration, but also quick to turn off; resulting in the gas engine turning on/off more frequently than in eco mode.

This has a potential of higher wear, but I think less of wear than eco mode, where the engine is nearly always strained by accelerating the vehicle while charging the battery. 

 

Edited July 28, 2021 by MeeLee