I’m going to say the 6.4 with 8 speed towed my Car trailer like it wasn’t there. I have had issues with the transmission randomly shifting into neutral which has been an ongoing headache. However, I researched 2500 series trucks for about 2 1/2 months before I bought my ram. I talked to a few dealers down south that were very honest with me in explaining that my driving habits did not work well with the diesel, and might lead to issues. I can tell you that if I were offered another 6.4 with the 8 speed I would take it. I believe my truck was a Friday afternoon or Monday morning production. I wish I could say it goes a camper well, but it’s been in the shop long enough I have missed 2 planned camping trips.