Totally normal with the newer engines. My 2013 5.3 will range from 30-45 when cold (idle to cruise) and about 20 - 37 psi when warmed up. I asked the mechanic about it and he said that is perfectly normal. I know when I first bought the truck I questioned it because I'm use to cars cruising at 60psi.
Drive and enjoy
🙂
2013 1500 Chevy PU/Crew LT