I've read about this problem on earlier models but not on the E70's. Today it happened to me after I filled up my 08 x5. Tank was 3/4 empty so filled up with 19 gallons of Chevron, drove away and gauge showed 1/2 full. I only have 2,500 miles on the car. Stopped, restarted and it was still at 1/2 full. Anyone else encountered this problem? Back to the dealer!