I think it would be okay. In VA one of the guys with a 4.7L Durango bought it with 70,000 miles on it and switched from conventional to synthetic and didn't have any problems.

 

i switched to amsoil at about 60000 miles...got about 82000 on it right now and haven't had any problems. i change it every 6000 but i'm about to store the truck for a while so i will probably change the oil early so i have fresh oil sitting in it while it sits.

 

Great site {BITOG} lots of info.
going to try Mobil 1 high milage syn or Esso XD3 syn, the only thing left is a filter, I read {BITOG} that Fram Xtended Guard or Purolator are the ones to go with.

 

I use Valvoline SynPower 5w30 (since I work there) since 42,000 mi. I have not had to add any since the change. No problems, that I know of...

 

yeah just gotta be carefull...if you haven't owned you dont know if it was taken care of and changed regularly!...so if you dont know you can change and it make be okay but if it starts knocking or leaking just go back to conv. But i started using synthetic at 10K and will never go back... I use Valvoline Max Life Synthetic...from what i've heard its the best protection...who knows i used to work there so i still get mad discounts so thats why i use it!

 

changed to royal purple at 63k. before that i had jiffy lube or something of that nature do the change because i had no time, got pissed at all the hidden charges and i think they through some cheap crap in there lol. no idea what the last owner had in it so who knows my truck might of been jumping back and forth between synthetic and conventional. runs like a charm tho

 

I switched over yesterday to Mobile 1 Extended Truck is at 61,000. Truck sounds great, Engine sounds like its struggling less to hit the same RPM's I LIKEY

 

ok,ok....going to switch this weekend...i'm a believer again....lol

 

I've always used syn oil in my Jeep. Made a huge difference. Going to be doing my first oil change on my truck soon. Should I stick to what the manual says and put 5w-20 or go with 5w-30?

 

on my third round of Mobile 1. Last change was at 6000 miles / 7 months. Everything looks good except I got out just under 5 quarts and I put nearly 6 into it.