How do I diagnose my fuel economy problemI have dual 100 gallon tanks on a 2009 kwt660. When the red light comes on at the gauge near empty I can only put in 120...
Answer to "How do I diagnose my fuel economy problem"2009 Cummins ISX 400 ST.
Answer to "uneven fuel return, 2010 kenworth t660, 450 ISX cummins"I have dual 100 gallon tanks. When the red light comes on near empty I can only put in 120 gallons max. Also after 150 miles of driving a quarter tank will be depleted from the information on the fauge. The Ecm says I'm getting 7 miles to the gallon. The math I do says six. But using both those numbers I cannot match the gauge readings to the mpgs. I already had an overhead done and a new dpf installed. What could it be? Fuel restriction, sending unit, gauge calibration, or bad engine?