Cascadia 2015 and Cascadia 2014

APU is something else to go wrong, but that debate won't go away.

I was going to point out that date of build and date placed in service, and other factors, can affect the mileage of a truck of a given model year. The 2013 I normally drive was built in 6/12, I got it on 8/12 with 2k on it, and due to several factors, only has about 400k on it, but idled significantly so it has above normal hours for the mileage.

I drove a 2014 just a month, and it was immediately apparent that it ran better and got better fuel mileage.

The 2015 probably is an Evolution engine or could be, that went to an asymmetrical turbo in place of the standard old style, which made it more responsive and gives better engine braking, ditched the turbo compounding, as far as I know, and lots of other improvements as mentioned in previous posts. There are lots of used Cascadias floating around out there with the red Cummins under the hood, too, just saying

I like open tanks and steps for what I run, but those are getting more difficult to find. Evolutions most likely have full aero treatment, at least the ones with sleepers.