I just traded my 05 3500 quad cab slt in on an 07 2500 mega cab larmie and the dealer says that there is ULSD oil that i have to use in the new 6. 7 motor. Also a friend of mine just had his oil changed for the first time in his 08 3500 and said that i was over $100 at the dealer. So if anybody can give me some info about this that would be great.