I've always heard the amsoil makes the best synthetic oil, they were the first to make synthetic from what i've heard, i know alot of people use shell rotella t synthetic or mobile 1, but one of the my family members has an account with amsoil and can buy at wholesale, just want to see if anyone is running amsoil, heres a link to their webpage on synthetic diesel oil:
AMSOIL Synthetic Diesel Motor Oil, Engine Oil

 

The rule of thumb: cheapest all synthetic xW-40 beats the best xW-40 dino oil.

 

I like the Rotella 5w40 Syn! Made a huge difference in my truck....cheap too! Well, cheaper than the others.

 

i've seen amsoil in action, not in diesels but in airboat gearboxes, it's good oil

 

Even at discounted prices...Amsoil is a little overrated and over-priced. There are many to choose from....but as long as your looking at Amsoil...check out there oil bypass filtration. Mobil1 HDD 5w40 Syn is all I ever use.

 

I think Royal Purple has better qualities than Amsoil and use nothing else in my Harley. BUT, they do not make a cj-4 oil for our trucks yet. They do have a CI-4+, but I'm not sold on that it's the best for our finicky engines.

I'll stick with the Rotella Syn.

 

thanks for input, ill see if i can get it wholesale, but synthetic rotella t is my second option

 

Mobil1 does make the CJ-4 ....but it is really only necessary in the '08+ engines. I have ran Mobil1 HDD 5w40 CJ-4 on my last three oil changes.

 

Ive never run amsoil. My engine seems to run smoothly with Scheaffers & Motorcraft Synthetics. Like said above a lot like Rotella T and it is easy to find and a good price.

 

I use Rotella T Syn and it is a good oil. I am sure though that any syn oil that is cj-4 rated is a good oil. It is convenient to be able to go to about any Wal-Mart and be able to pick it up though.

 

On my 3rd round of Mobile 1 Turbo Diesel. Truck starts great now and runs really well. With Motorcraft, my 6.0 started really choppy in just freezing temps. Now that has not been a problem when changed over. I am confident in Mobile 1 as I have used it forever in everything else...that I still have.

2 outta 3 Wallyworlds carry it in my area.

 

It is really a personal choice. I have always run Amsoil in both my farm equipment and my F250. I have often wondered about trying something less expensive. But I have never had any oil related issue with it and hesitant to change unless I need to.

 

I have nothing against Amsoil however, it has been posted that Amsoil states they they are CI4+ rated but they fail to carry the API rating on their containers. I for one will not take the chance on my 15 grand motor with a company that cannot back up their claims with the API rating.

 

Agreed. All oils are not created equal, however IMO if you use any of the major brands of synthetic oil, change it at recommended intervals, and use Motorcraft or Racor filters you and your truck will be happy for many miles.

 

I'am using Chevron Delo 400 5w-40 synthetic it is good stuff I'am on the second change with it and never going back to dino.

Amsoil is too over rated I don't like the fact they they are trying really hard to push their oil. H*ll you can become a dealer if you want.