I purchased my '13 2500 cummins last week and filled it up last night for the first time. It was a pain in the azz to get the nozzle to not pop and stop filling the tank. I could NEVER get it to go "full" on and had issues keeping it on the first notch so I didn't have to sit there and hold it the entire time. This is my first dodge diesel, my previous truck was a F350 I had for 8 years. Was not thrilled to see a capless design last night when going to fill it, and really not impressed when its a PITA to fill for some reason. I can wait until I get a truck pump to try and fill it if it cant take the automotive style.