EPA,Hypermiling

Be Conscious of How You Work the Accelerator

27 Feb , 2016  

– Tony Schaefer

At its core, driving a car is ridiculously simple: two pedals and a steering wheel. However, like many things, it’s how you minutely manipulate those three items that differentiate the bad from the average and the average from the good. In this article, I want to address how you manipulate the accelerator pedal.

Has anyone ever told you to press the accelerator as though there’s an egg under it? The point here is to make sure you do not stomp on the pedal so hard that it would crush an egg. It’s meant to make you aware that you should drive with a light foot. I tend to take that one step further and push my seat back as far as it will go.

The original reason I pushed my seat back is that I can’t stomp the pedal to the floor if I literally can’t reach the floor. But then I started analyzing what was going on by messing around with various seat positions. Here’s what I discovered:

  • When my seat is forward, I tended to use my whole leg to work the pedal.
  • When my seat is back, I can only use the flexing of my foot to work the pedal.

This, in my opinion, is a huge difference. Your thighs are very good at pushing a lot of weight; you see this every time you stand up. Whatever you weigh, your thighs can push that much weight and more. Unfortunately, the pedals of your car do not require that much force and your thighs are not very good at minute, controlled adjustments. For this reason, controlling the accelerator by straitening and bending your leg will result in jerky adjustments.

Your calves and foot, on the other hand, can make very small adjustments as needed. This is the type of pinpoint control you need when you are trying to precisely control your accelerator. And this is why I keep my seat back, plant my heel on the floorboard, and use the flex of my foot to move the accelerator.

At the same time, your foot’s ability to slide on the pedal makes a huge difference. When you are using the flexing of your foot to control the pressure on the accelerator, it requires a certain amount of slippage between your foot and the pedal.

I need to be very clear that when I refer to slippage or sliding, I am referring to a controlled amount of movement between two objects; like when you rub your hands together to keep warm. In no way am I referring to an uncontrolled slipping and sliding like an awkward person busting their butt on ice. Do this: put your hands together, palms together, fingers extended. Now push with one hand’s fingers making the other hand’s fingers bend back and then go the other way. Do you feel your fingers slightly sliding against each other? That is controlled slippage and sliding. That’s what I mean.

In order to avoid the driver’s foot from slipping off the accelerator, most cars have a pattern etched into the pedal. Shoes with deep tread might grip this pattern and not allow any slippage between the bottom of your foot and the pedal. These are winter boots, tennis shoes, and the like.

In my experience, shoes with a smooth bottom are the best for allowing a controlled amount of slippage. These include dress shoes with leather soles or any solid bottoms that are inclined to make you fall down if walking on wet grass. Next time you’ve just butt-planted in the morning dew, make sure and point out that your mileage is better than any witness’; that’s sure to make them stop laughing. No, not really.

Now that you’ve got your smooth-bottomed shoes, it’s time to think about how to feather the accelerator pedal. Have you ever needed to push a car? Ever run out of gas or be on a road trip with a buddy who ran out of gas? I mean, how hard is it to notice that your gauge is on “E”, Chuck?! And who has to push the car? Certainly not Chuck; oh no, he gets to sit and steer while the rest of us get out and push. What a crock!

Anyway, if your buddies are as fuel-negligent as mine, you might remember that the hardest part of pushing a car is getting it going from a dead stop. Once you get it up to a decent speed you can pretty much just walk behind it laughing and making fun of Chuck. Until you reach a hill; that’s a whole other story. The point here is that the amount of effort required to maintain a speed is substantially less then the amount of effort required to start moving from a dead stop.

This is where much of the fuel efficiency comes in. Once you are at a decent cruising speed for the section of road, slowly start easing off the accelerator. Eventually, you will drop one MPH or two. That’s when you lightly ease back on and maintain speed. From that point, all you should need to do is feather the pedal a little harder or lighter based on need.

What you are looking for is that sweet spot where your car’s engine is using the least amount of effort to maintain a constant speed. If you press too hard, there’s a chance you will rev up the engine without actually accelerating. Press too lightly and you risk slowing down which will result in the need to accelerate back up to speed. You will be required to constantly monitor your speed and the car’s effort and then make any adjustments. This is attentive driving at its finest and can actually be very mentally taxing.

Conclusion

Move your seat back to keep you from using your entire leg to manipulate the accelerator. Use the flexing of your foot to control the amount of pressure on the pedal. Wear shoes that allow a controlled amount of slippage between your foot and the pedal.  Never go on a road trip with Chuck.

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