Filled the tank on my 550i with 400 miles on it at the interstate entrance and zeroed the mpg counter. Once up to 70 mph I set the cruise and headed for the turkey dinner 90 miles away.after about 30 minutes the average mpg was trying to break into the 30 but never made. The average traffic flow was 80 mph.
Got bored and played in traffic the rest of the way. Love how the tach is at 1900 at 80. Average mpg was 28 ish when arriving for dinner.
It isn't broken yet but I can fix that!
2013 550i Titanium Silver Metallic Dinan S3 , BMW F800ST, ML350