Fuel log data is handcalculated at the pump. I fill the tank every time up until i see the fuel at the top of the hose. So fill ups are with a verry small error. Scangauge is set up and is accurate within 3%.
Money saved in 2013 (start to ecomodder): 100€
Money saved in 2014: 460€
Money saved in 2015: 665€