does the trucks make less some in the winter. also ajusting the star wheel down adds more mid range power right?

 

Seems like on average, winter blend fuel will cut power by 10%. Also, these engines really need to build some heat for peak efficiency. It's just plain tough to get 'em hot when it's below 35*.

Running the starwheel down will allow more throttle rack movement for a given boost level. Once boost begins to build, a lower starwheel will build more power all the way to your peak boost #.