Can you recommend formula for calculating fuel consumption using OBD data for diesel engine? I find a article(http://www.windmill.co.uk/obdii.pdf) about fuel calculation using vehicle speed and MAF(mass air flow), but I am not sure the formula described in that article is applicable for Diesel engine. Any accurate formula for Diesel engine will be highly appreciated.

  • There are several relevant questions and answers on here, you should read this : mechanics.stackexchange.com/q/63098/10976 and this one : mechanics.stackexchange.com/q/27882/10976 – Solar Mike Mar 20 '19 at 7:17
  • You may also need stoichiometric combustion is 14.7 for gasoline and 14.5 for diesel... Check though.. – Solar Mike Mar 20 '19 at 7:23
  • @SolarMike Thanks. Is this formula for fuel flow rate is correct? fuelFlow = ((MAF * 3600) / (14.7f * 820)) / 10 ; // l/h – lei lei Mar 21 '19 at 0:40
  • The problem is that a diesel may run 5-80 A/F, and stoichiometric combustion is only an ideal. It will be useless to assume 14.5 in the calculation, as the actual operating point will vary wildly and spend little time at stochiometric. This has been asked before, and the response rate of OBD II data is probably not going to yield good results on anything but a long-term analysis. Diesel, gasoline, or otherwise. – SteveRacer Mar 22 '19 at 3:35