We have during the last month checked out three customers RV's for either servicing or minor faults, we have found on EACH one the same fault that they never knew about. Each one had the cooling fan locked in causing excess fuel consumption and over cooling, two of them also had the power setting set wrong, one was set at 260HP when it should have been 350HP. Both of these together added to their fuel comsumption. We reset their fans and did a power output check and they are now saving between 2 and 3.5 MPG not to mention the fact that it also saves on engine wear by not overcooling. From your point of view it may be worth checking this to ensure your dealer has reset the ECM and it is not still on its default settings. If you have an Allison MD series gearbox, these can also be reset to perform various functions other than the standard default settings, such things as using the gearbox as an integeral retarder, or if you have hard shifts, these can be reset as well. We have found some that have run low on transmission fluid that then develop a hard shift, this can be removed from the ECM and it will re learn the best shift pattern. Have a great weekend all of you out there!!!