Would i run amsoil? sure.
They make excellent oils.
And it might even be worth the price if you do long long oci's.
But i bet you don't.
I'm doing 10k oci's and extending (aiming for 15k or so, i started at 6k) with m1's tdt.
If you don't know what tbn is, or don't do oil analysis, you dont need amsoil.
If your changing your oil at 5-7k miles, I would use the least expensive easily sourced synthetic 5-40 in your area.
Witch would most likely be shell Rotella t 5w-40 at wall mart (BLUE BOTTLE) for around 19 bucks a gallon.
Take the cash you save and buy a better air or oil filter, or a ehm or whatever.
Or you could pay 26 + dollars a gallon for tdt and know your running one of the best oils on this planet.
The crd is not particularly hard on oil, but it can have a high soot load, and tdt handles it really really well. I have seen some uoa's in the past that showed really high wear metals (like 40+ fe) for various oils, and that scares me, because i'm usually in the mid-high 20 range, so unless your getting uoa's, you'll never know the difference anyway. (and in the case of <8k or so oci's, there may not be a significant one anyway)
It's your truck and your money, and your comfort level, and they are all different.
Some people simply like changing their oil. Some people like to know that they have put the best in there that they can buy. (witch a lot of people seem to think is amsoil)
Some like to get the best deal and protection possible by buying smarter and changing with uoa.
Bottom line for me is that i would be 10000000% happy with rt syn in 5w-40 with a wix or m1(301) filter for up to 7k (get a uoa for the first couple runs) That's going to fit the style and price for probably 95% of all crd users right there. You cant get much better for the mileage.
I have had exellent results with those products and mileages, and so have others here.
read some of these
http://www.lostjeeps.com/forum/phpBB3/vie ... sc&start=0
And go to bobistheoilguy.com and read there, and google up oil analysis
Again, you cant go wrong with amsoil, but it's not necessarily better for you. You could save the money and get the filter mod and a nice wix filter, or even a amsoil filter.
It's cool to get oil analysis. If your environment and driving styles are the same or similar, you can track changes with them, easily.
Like lowered si due to better air filtration, or less off roading. Or lowered wear numbers with reduced soot load, due to blocking off your egr.
Or finding a injector leaking before it destroys your engine, via the fuel contamination of your oil.
Edited for spelling, because i fail. :P