We asked our dealer why the computer in our Highlander Hybrid regularly says we're getting about 1.5 - 2 mpg better than we calculate manually. The mechanic thought that the Highlander probably has the same rubber bladder in the fuel tank as the Prius, and that therefore we aren't necessarily filling up all the way. I really like this explanation, because that means we're getting better mileage than we thought (27.8 average calculated manually). Is this true? Is there a bladder in the HiHy?

If so, is there a way to go back and edit the tanks I've posted in the compare area? I did keep a record of what the computer said for each tank.

Katie