This has been long overdo, but should any of your readers experience what I did after purchasing a used vehicle and didn't gey any where near what the specified MPG was, have them get their mechanic to look into the "adaptive learn strategy". As a last resort, the service manager had the ALS reset. The MPG instantaneously reverted to what the model called for. Thought you might like to know.
I just purchased this vehicle in April 2011. Since I started to drive it the MPG has been at best 20.5 city and at worse 16.5 city. The dealership has performed three major mechanical cleans (even though it isn't ready for these yet) on the fuel filter, ejectors, etc. They said the oxygen sensor is good. I wanted the ECM upgrade performed, but was told it had been done already. Since getting the vehicle back from the dealer, I have only been able to get 21 MPG city. What are they missing to check for?