Is it just me or does the cummins engines just get louder as they get more miles on them? Dont get me wrong I love the sound, but it just seems odd to me.

 

I have found mine changes with the season. The warmer the air, the quieter she runs. Also, SHe runs almost silent after a long pull with the trailer or longer road trip. I think it has to do with how big the bloc is and how long it takes to really heat it up. In the winter your water temp could be warm but the block and cold air could keep it cooler.

 

its from the components breaking in my 07 changed sounds at about 24k when i was going down the road