Ive got the 2.8L thanks for all the responses!
I drove it for around 2 hours and where it usually shows the MPG your using at the time on the dashboard it disappears around 2 hours of driving, This happened to me when i took it out for a road trip last week

. I parked the car and went shopping and once i got back in and started it back up it was fine. Any clues on how to fix this?