I've been experimenting for some time with fuel economy since buying a car (Skoda Octavia 1.9 diesel) which offers a display of the instantaneous fuel consumption. This is a useful feature which offers feedback on driving style - and I confirmed the established truism that a heavy right foot on the accelerator lowers consumption.
To step back from this observation - there are of course many other factors which reduce economy:
- short journeys (especially in a diesel, which takes longer to reach efficient operating temperature)
- getting from A to B as quickly as possible
- maintaining speed up hills
...and I assume that anyone who is keen to reduce consumption of our fossil fuels will be aware of the basics. My intention is to take this interest forward.
The right foot in a car is placed on the pedal in a way which makes it able to apply large force (using the calf muscle). This is very useful in braking - although this is nowadays not necessary due to power assistance. The fact is, however, that this arrangement does not make fine control very easy. The large muscles of the leg are designed for locomotion - fine muscular control is available only at the end of the limb. An analogy would be to imagine having to do what you normally do with your hands if they were encased in a shoe.
"Dynamic Tension" (with apologies to Charles Atlas!)
Another observation: when driving the right leg is typically held in a position of tension - the antagonistic muscles of the calf and shin maintain and vary the angle of the ankle. This is fine when standing or walking, but I wondered how it might be if the major leg muscles could be allowed to be at rest. Of course, the right foot must always be available for instant action to operate the brake - but I haven't found this to be a problem.
So - I made a rounded “platform” or ledge close to the right hand side of the pedal. On this I rest the right side of my foot, and the left side of the foot touches the pedal. In this way, rotating (or to use the technical term, everting/inverting)the foot rather than using the gross movement of the ankle produces much more controllable pressure on the accelerator.
I experimented with various materials, and finally built up laminations of carpet tile with a glue gun. This is shaped to fit the contours of the car interior and attached with Velcro to the carpet lining.
(A digression – when people have shown an interest and asked how they might do it, I have found that some cars do not have a lot of room to the right of the accelerator pedal. I’m just thankful that the Octavia does!)
Taking care to get the right arrangement, the result is a foot-rest which enables me to have fine control of the accelerator. Since I have installed it the overall MPG of the car has risen to around 57. Using care I can get 70+ and indeed even short quick trips are rarely under 50.
Raw competitiveness
It's quite easy to develop new habits and get used to the lower average speeds which result. And I've also found that my competitiveness (which used to manifest in seeing how fast I can get from A to B) has now shifted. The pursuit of economy can substitute for more destructive urges - I'm sure it's all part of the macho spectrum, but less damaging to the planet.
And it's catching - my wife will come back from a trip in the car glowing with pride and punching the air announcing "I got 60!!" It might be something to do with the ageing process, or perhaps an evolving awareness of our global responsibility - but playing games like this is fun!
I'm grateful to Charlie, a physiotherapist friend who discussed this project with me.
