I am able to capture the engine load at a point in time. What if I calculate an average load for a commonly traveled route? I can then take variations of that route and determine which path minimizes the impact to the car. I could factor a lot of variables including time, distance, average engine load, gas consumption, frustration, etc. I could then determine a set of heuristics that could suggest the optimal path.
This could be useful for frequently traveled routes like to and from work daily. Or any other profession that does a fair amount of repetitive automobile travel. I believe the software could just sit there gathering information with little input from the user. This would allow it to collect a vast amunt of info and make decent determintions based on user preferences.