I have a 5.6L with ~800 miles now. Last tank I ran 277 miles before the fuel light came on and mpg showed 13.6 on the computer but hand calculated at 12.7. This was about 30% highway 70% city. Driving very conservatively, never got above 70 mph and 2000 rpm. This same mix of driving would net 15 mpg in my 2015 Titan. Please tell me it gets better than this.