MP3Car.com - View Single Post - Calculating MPG from VSS and MAF from OBD2

PTSchram · 07-22-2006, 03:17 PM

Quote: Originally Posted by JML

2. Some gasoline may have different octane grade and modern cars will automatically tune the mixture ratio.

Fuel Mass = Engine Mass Airflow / (Stoichiometric Ratio*Lambda)

JML

The lambda sensors are used to compensate for the varying grades of gasoline (well, they compensate for everything and only look at the composition of the exhaust gases). I suspect your correction calculation would be close enough.

07-22-2006, 03:17 PM	#8
PTSchram Newbie Join Date: May 2006 Posts: 21	Quote: Originally Posted by JML 2. Some gasoline may have different octane grade and modern cars will automatically tune the mixture ratio. Fuel Mass = Engine Mass Airflow / (Stoichiometric Ratio*Lambda) JML The lambda sensors are used to compensate for the varying grades of gasoline (well, they compensate for everything and only look at the composition of the exhaust gases). I suspect your correction calculation would be close enough. __________________ Watch out, I have a soldering iron and a ham radio license (it's worse, it's an extra class license too!) and am not afraid to use them!