Players: you, as a car driver and social network actor.
Playfield: your daily mobility.
Prize: the glory ! Demonstrate your environmental consciousness, and practical mindset, minimizing the time you need the engine running, given your realistic journey.
Fundamental step: evaluate as precise as possible how much of the time you spend moving in your car and you need the engine running. I can obtain in my actual town about 20%. So, 80% of the time my engine could be off. What I ear, seems foolish ? If you have a bit of patience, you can take yourself the precise measure: it would be a clip of the RPMs your cockpit shows. Why so ? Because your engine must be non idle when accelerating, but once reached the speed, inertia will keep your car moving without any support from the engine. Now, sure the 20% of active engine usage spits more than 20% of emission, but how much `exactly` ? Since RPMs are an almost linear indicator of the combustion process, here we have it. Will be the SW (in case it will ever see the light) to compute precise numbers, but right now would be more important to get your attention on this, worth to repeat: the engine could be off (0 emission) for 80% of the time.
Now, because of the implementation of our cars, right now you cannot take off the engine just because it’s proven useless. It’s not entirely useless, there are subsystems – like assisted steering and braking – that could need rethinking, and the temperature/pressure of lubricant must be accounted for, but without problems, there would be less fun in hacking the system, no ?
Let’s start just measuring it, do your journey, put your engine in idle mode (as soon and most you can) and publish your results, by means of a clip you can easily capture with your smartphone. Only RPMs and speed are relevant, so just a small part of the cockpit. And when you are confident it doesn’t violate the privacy of anyone (you included :), publish the real world GPS coordinates of your journey. Maybe you’ll get a gauntlet !
Disclaimer: pure fantasy so far, but cause I’m a SW engineer, I’m tempted to implement it.