Accelerator tactile resistance points to help mpg

The idea here being that there is a step increase in foot pressure at 2 or 3 key position points in accelerator pedal travel so that one does not have to resort to constantly monitoring the HSI indicator to give feedback on accelerator pedal position. One of the key position points would correspond to the border between the regen/EV region on the HSI. A 2nd possible point would be midway in the right half (engine on) region of the HSI. A 3rd possible point would be just at the right edge of the PWR region.

I think this would benefit hypermilers (safety - less time looking at HSI) and allow regular drivers better mpg - by increasing likelihood of Prius powertrain being at operated at optimum efficiency points (for example, high pedal force to go beyond the right edge of the PWR region.

I do have a some DIY rough proposals of how this could be achieved. I'm still debating whether I should set the force step increase points according to the ECO or Normal mode - I'm leaning toward the Normal mode as my wife does not like the throttle response in ECO mode and knows nothing of hypermiling.

I'd attach a sketch jpg if I knew how. (Uploaded file but it won't show)

 

So about 4 weeks ago, after a bit of searching for ideas on this, I placed one of those "half sphere" hollow soft door stops that you can get in a hardware store see this Door Stop , in the foot well behind the accelerator, and I must say it's exceeding my expectations.

When the gas pedal is about 1 inch away from full travel one can easily feel the increase in foot force. The point this occurs equates to middle of the PWR region in the HSI, when in ECO mode, and equates to just to the right hand side of the PWR region when in Normal mode, areas where acceleration is still fairly efficient in terms of BSFC (within about 5% of optimum) along with the benefit of keeping up with most traffic. Just what I wanted. Note: this half sphere door stop is about 1.25 inches thick and there is the nice noticeable step up in foot pressure but not so excessive that one cannot easily compress the door stop when one may require fast acceleration in an emergency.

Believe it or not I did not have to attach this , I just placed it behind the gas pedal about a month ago at about a 30 degree angle on the floor and it has stayed put ever since.

So safety-wise I don't have to look at the HSI when accelerating from a stop, or when I need to get up to speed after slowing down. So I feel this is one step closer to making high mpg driving easy. My next endeavor is to make a step increase at the CHG/EV border and just to the right of the EV/"engine on" border on the HSI. Right now I have a few different springs I am working with to set at least one more tactile response points, so I can get closer to not having to look at the HSI at all. Actually my wife (who doesn't want to hypermile) may end up hypermiling without trying. It would also be nice to have a tactile response point on the brake at the point of maximum re-gen. Any ideas welcome.

 

The door stop solution mentioned is still producing dividends, but being one to never turn down an opportunity on further improvement and trying to eliminate springs or any physical attachments to the "go" pedal for safety amongst other reasons, I'm now thinking about strategies to ease the comfort of reaching and maintaining any given gas pedal position. So the thought is that rather than having one's foot only pivot about one's heel at the lower back of one's foot which is controlled by both the calf muscles (increase "go" pedal) and the tibialis anterior muscle (decrease "go" pedal), that one can instead also pivot about the right under side of the foot, which for most people may yield better finesse and more comfortable to sustain for longer periods. This could be accomplished by mounting an 8 inch high by 1/2 inch wide rest plate structure to the right of the go pedal parallel to the right edge of one's shoe. As it would only protrude a 1/2 inch out from the right of the foot well, it wouldn't likely interfere with other drivers of the car that may not see its benefits (high-heel wearers). Key criteria to be met include, the optimum mounting location. Should I progress with this, I will be sure to update here. One of my thoughts with this is that extremely fine control could be achieved when resting the right of the foot on this "lip plate" by moving the right knee left and right, and maybe reducing the amount of time one has to look at the HSI due to improved muscle memory potential (that is, moving 2 inches left with the knee, may equate to 1/8 of the HSI travel to the right, for example)

 

The HUD not in US cars, would be great, but I'm sure if one can eliminate watching the HSI almost completely, HUD or not, that is an improvement. Good point about HSI position not being an exact correlation of pedal position which does vary with speed, which can also be seen all the time when one accelerates from a stop. Not sure about SoC effect on HSI position for a given pedal depression. Also the power output at a given HSI position varies with speed, so 3/4 HSI at 30 mph has less kW/hp than 3/4 HSI at 60 mph, if I understand hobbit's findings correctly (BSFC moves right also with speed). Again in a perfect world we could have, say 4 customizable buttons controlling specific gas pedal/HSI positions, which could be customized for example, as "PWR right", "no-regen Glide", "5/8 efficient acceleration/cruise", and "7/8 efficient acceleration/cruise" with brake override for any of these settings, though in this sue happy world, Toyota would be reluctant. I don't think even cruise control, if it was a brand new concept, could be introduced in today's world.

Does anyone know if the Prius Gen III has had any Disabled driver conversions where the driver uses a hand operated throttle/brake?

 

Just to be clear my objective with this is to achieve efficiency while maximizing safety. In my opinion having to glance at the HSI HUD or not, lowers my safety and distracts me.

I concur "I don't want an accelerator pedal that is sticky or feels like it is." I think, cruise control can be dangerous, as it's providing motive power while nothing is "pushed" The mode buttons I suggest above would only give motive force only while depressed and the instant they are released, no motive power is provided, a "dead man's pedal" if you will.