it all comes down to what the upgrade price is. If is it 7-9k like in the HD's it wont sell much IMO, but if it was 4-5k i do think it could be successful. I believe most people on average drive something like 12000 miles per year. I think the mileage could be realistic if you drove at the speed limit and just cruised down the highway because in the LBZ i have gotten 22mpg hand calc'd driving that way. Most of the time it is 19-20 highway, but a smaller motor in a lighter vehicle could do very well. I also think this has potential in the suburban/avalanche vehicles. Just have to wait and see i guess.