I haven't noticed that our trip (neither A nor B) really fluctuates that much. I have noticed though that the MPG's shown are off from what I calculate manually after filling up. For instance this last tank, trip showed 46.7 MPG, when calculating it by hand I really averaged 53.1 MPG. I guess this is due to the programming problem that everyone it talking about and how the trip computer only calculates for the last 63 miles travelled.....?