I just happened across this post and thought i'd offer my
I have an 08 Caravan with the 35,000 on the 3.8L. I run 5,000 mile drain intevals and am using Valvoline 5W-20 oil and Mopar filters. Starting around 20,000 miles it started using a quart between the changes and is reading low when I do the oil change. I suppose the consumption rate is about a quart evert 1.5 - 2.5 K miles, high in my opinion, but not to the OEM. I also had a 2004 Caravan with the 3.8 and experienced the same oil consumption, around 1500 miles per quart by the time it had 100K on the vehicle and we traded it in on this one. I never had any issues, It just ate oil for the entire time we owned it. I'm assuming it's just this engines, ring package etc...