On Thu, 5 Oct 2006 21:32:37 +0000 (UTC), "TeGGeR®" <tegger@tegger.c0m>
wrote:

>"Chris" <criro1999@gmail.com> wrote in news:1160064779.892720.143910
>@i3g2000cwc.googlegroups.com:
>
>> Is there any way (formula) to calculate the fuel consumption (e.g.
>> L/100 KM or Gal/Mil) from values read from OBD-II interface?
>>
>> I think next values could be taken into consideration to compute the
>> fuel consumption, but I don't know how exactly to interpret the result
>> of them:
>>
>> Short Term Fuel Trim
>> Long Term Fuel Trim
>> Mass Air Flow
>> Fuel Pressure
>> Accelerator Pedal Position
>> Throttle Position
>> RPM
>>
>
>
>
>I seem to recall seeing a laptop-based OBD-II diag system that was capable
>of the sort of number-crunching you need to do. I don't seem to have
>recorded the maker, though.
>
>Laptop solutions are software-based, with an adapter cable that conects the
>OBD-II DLC port and a USB port on your laptop.

Or you can buy one of these:

http://www.scangauge.com/

I bought the older and much clunkier first generation model. It works
very well and does all of above and more. ON caveat: fuel
consumption and related values (like miles to empty) are accurate only
to within 10% and perhaps more. Good for determining how speed
affects your fuel consumption but it doesn't replace actual fuel
consumption measurements made at the pump and I wouldn't use it to
decide whether I could make it to the next station.