Cummins12V98 wrote:
"You can also use a 28mm 6 point socket as well - which will fit better as it's metric to begin with."
True the 28mm is the "correct" size 6 point socket. BUT I mentioned the 1 1/8" socket since more people may already have that size. 1 1/8" is equal to 28.5750mm so the 1 1/8" socket is .575 mm too large. THAT will not make a bit of difference. So use what is cheaper or what you have.
I have used my 1 1/8" 6 point shallow impact socket at least 6 times between my 11 and 15 RAM.
Some opinions may vary, but changing that front filter, IMO you want to give yourself every chance you can to succeed. Many have ruined that plastic cap either using the wrong socket, wrong angle ,whatever.
I too have the 6 point 1*1/8 socket, but still went with a 28mm on the second change, like the fit much better. For 6-8 dollars not a big deal. If one can afford the truck, why skimp, use the right tool.