Calculating Diesel Fuel Consumption / MPG (OBD2) - Help needed
I'm a new user, but have been lurking as guest for quite a while. Anyways, I'm seriously hoping for some kind of help to achieve some accurate diesel MPG readings for my Car-PC application.
I've been trying to calculate MPG using Bruce Lightner's Formula found here:
Also read this topic:
I'm developing a WPF/C# application with some basic information and a really nice design. For that application I would like to display Fuel Consumption as well. Screenshots can be posted if you're interested, however I'm not that far into the development yet since the MPG issue has been stalling it.
First of all, here is a readout from my OBD2 application while driving ~50 Km/h. The data has been verified thru multiple OBD applications. The car I'm driving is a 2011 - Peugeot 206+ 1.4 HDi (Diesel).
MAF = MAF Air Flow (Grams/Sec)
VSS = Veichle Speed (Km/h)
MAP = Intake manifold absolute pressure (kPa (absolute))
IAT = Intake Air Temperature (°C)
CER = Command Equivalence Ratio
EL = Calculated Engine Load Value (%)
-- 02-04-2013 21:13:34 --
-- 02-04-2013 21:13:37 --
-- 02-04-2013 21:13:40 --
Using Bruce Lightner's Formula with the last readout looks like this (C#.NET code):
// Diesel Density
double dieselDensity = 7.079;
// Veichle Speed (Km/h)
double VSS = 50;
// MAF Air Flow Rate (grams/sec)
double MAF = 11.99;
double result1 = (14.7 * dieselDensity * 454 * (VSS * 0.621371))
// result1: 1467797,30076021
double result2 = ((3600 * MAF) / 100);
// result2: 431,64
double MPG = result1 / result2;
// MPG: 3400,512697526202
That gives me 3400,51 Miles Per Gallon! Thats quite an economic car I got there if it was accurate, but obviously they are not. I must be forgetting or overseeing something, I just don't know what? So any help would be appreciated and please dont hesitate to ask if you need any further information.
Other formulas and calculation methods are welcome, right now I'm just eager to get something to work since I'm kinda stuck with these results.
Thanks in advance for any help :)