I've seen the group IV thing mentioned before, I don't know what that is?

I like using Amsoil but the last 2 oil changes I have used Rotella Synthetic 5w-40 do you know what group that falls into?

 

Rotella is made with group 3 basestocks. The groups just refers to different classifications of basestocks. Group 2 is typically today's stocks from the ground, your dino basestocks. Group 3 have received the term "synthetic" although still made from highly reformed petroleum oil. The group 4's are the chemically made..in the lab, so to speak. An example is PAO's.

 

That's the same oil I use, and I have over 230,000 miles on my truck with varying lengths of time and mileage between oil changes. My truck used to always take two or three tries to start up on cold days no matter what oil I used, Synthetic or Dino and plugged in or not. But since I did the HPX mod, it starts on the first try every time, even up in the freezing temps of Truckee Ca,.

All things being equal, synthetic oil is the best choice if you can afford it. I used to have a report, let me see if I can find it again that showed Amsoil beating out Mobil 1 in a lot of areas besides friction wear.

 

Thanks for the explanation.
I changed the synthetic RotellaT at 10,000 and used the scientific test method of still feels ok between thumb and finger.
I think I will go back to amsoil next change and eventually install a bypass filter on it(been meaning to do that).

 

Group IV means that the oil is fully synthesized from synthetic base stocks (meaning that is does not contain conventional petroleum products). There are a few other Group IV synthetics on the market that I failed to mention, but I think I got the major ones. To find out which oils are and are not fully synthetic, you have to usually look at the product MSDS.

You have to be careful in choosing synthetic oils. Many on the market claim to be synthetic but are not FULL synthetic. For example Shell Rotella SB - is a Group III (meaning it uses some dino oil as basestock), which puts it in the same class as the better conventional dino oils (even though its supposed to be "synthetic"). Just because an oil says its synthetic - doesnt necessarily mean that it is. But, if you are buying a good Group IV Syn - you can be sure you are getting the best for your engine and getting your moneys worth. i see after I typed this that Heath already explained it.


Welcome has some very good info.

 

I remember seeing that page before thanks I forgot about that guy.