auto mobile journal

[eluser]Sally D[/eluser]
what would be the way to find out how many gallons of gas you used by the amount of time you had the engine running

what is the formula for that? I had to much grappa and I am feeling dumb. I have a netbook that I take around with me, so I want to write a script an auto log so that every time I drive I can make a log of it.

[eluser]rogierb[/eluser]
There isnt a real formula since it is based on a lot of variables like windspeed, wind directed, drag, engine power, fuel type, tires etc.

The only thing you can do is create a formula based on average speed and distance. But you have to have an average fuel consuption ratio in advance.