A calculator?... "i am doing 64.5 mph i am still at 111.12 miles from destination... hmm let me bring up the built in calculator to see how much time i still need".
Your restraint in not using speed as the independent variable is admirable.
With fuel prices on the rise again, it'd be great to track fuel efficiency against a ton of different variables--you could find out if you really do get better mileage by lifting off the pedal slightly when you hit your cruising speed, and what temperature and humidity do to your mileage, etc.
My father keeps a pocket calculator in the glove compartment to calculate what his mileage was between fillups. Having one built-in would certainly be useful for people like him.
Not sure if you're being humoristic, but any car advanced enough to have this IQon technology most probably also has a regular basic in-car computer, and those tend to track mileage by default. You don't even have to key in the numbers.
Not being funny - he actually has a Prius which does give MPG readings, but he finds that it's not that accurate. Just because a car has a fancy in-dash computer doesn't mean that it's any good at keeping track of its own fuel consumption.
But with access to the CAN bus, you can write an app to calculate milage automatically. You can analyse mileage for a cold engine, between fillups (remember you have access to the fuel gague), by road (GPS tracks) - some pretty interesting options.
