It is important to look at the diesel resale as a percentage of purchase price, it keeps things more real. Same as the gas option. Another way is to look at it is by comparing them by a cost per mile. When you combine the two you can get a better idea of where the money is (if that is important to you). If you pull at the upper end of the trucks capacity the less the dollars matter and the gas trucks are not an option any way. My personal experience is the gas HD trucks I have had did well for me on trade in on a cost per mile basis at trade in. I was happy. The numbers are always in a state of flux, the region of the country your in, the economy, how the trade-in is loaded are all factors. However as the gas options become more capable, they give the buyer more options and that is good. There is more overlap in the area that either engine option will work then there has ever been. We can argue about which is better, at the end of the day, all that matters is that there are legit choices to pull with.