Amsoil 15W40 CJ4 vs Amsoil 15W40 CI4+

Joined
Feb 24, 2009
Messages
74
Location
Niceville, FL
Just wondering if the new CJ4 is as good, or better than the old CI4+. I have been using RTS for the past 20K miles. With no problems, but people think that I'm crazy for using a 5w in the Texas summers. What's ya'll opinion? Thanks Kevin
 
Joined
Oct 5, 2006
Messages
19
Location
NC foothills
What difference does the 5 wt matter. At operating temp is it not a 40 wt? Please correct me if I am wrong, because I have 5W-40 Scheaffers S-9000 in my Cummins. It was 103 when I came thru Atlanta yesterday on way to Alabama. Am I missing something? Shoud Kevin and I use a 15-40?
 
Joined
Jul 31, 2005
Messages
20
Location
South Carolina
IIRC the W is a pourablility rating for Winter use...That is to say that at colder temperatures it flows or has a similiar viscosity as a 15 oil. A straight 40 weight flows at the same or close to the same over a wide range of temperatures.
 
Joined
May 27, 2002
Messages
14,013
Location
Retired | Wausau, WI
5W-40 is just fine in all of the above applications. As for as the two Amsoil oils listed, if I had a diesel that required the CJ4 spec I would use it without question.
 
Joined
May 11, 2007
Messages
1,267
Location
Tennessee
Yes, do not worry about the urban legends of people saying "5W-30/40" is like water. The 5W part of 5W-40 only applies to the cold start as far as viscosity goes. There are 0W-30's that are thicker than 10W-30's out there when it comes to being put under heat. A different example, though, would be comparing Rotella-T 15W-40 and 5W-40. The 15W-40 has a viscosity of 15.9cst @ 100C, while the 5W-40 has a cst of 15.5 @ 100C. If I remember correctly, the 15W-40 has a viscosity of 115cst @ 40C, and the 5W-40 is 90cst @ 40C.
 
Joined
Jan 26, 2005
Messages
40
Location
Canyon City Oregon
The question I have not seen covered, is exactly WHAT differences component-wise, between Amsoil's earlier plain CI4, and the later CI-4Plus? In the DELO 400 I use, the major difference is the addition of Moly and Boron in the CI-4Plus - what did Amsoil change between the 2 oils? And unfortunately, in the DELO 400, when the later CJ stuff was introduced, the absence of the Moly, Boron and Zinc anti-wear compounds was quite obvious... So, my NEXT question is, HOW can the later CJ oils match the anti-wear capabilities of the CI-4Plus lubes, when they REMOVE significant wear-reducing compounds? Even the makers seem sensitive to that fact, by recommending shorter change intervals...
 
Joined
Nov 23, 2005
Messages
1,528
Location
Bohica
Delo still has the moly and boron, but it's less moly and more boron...they (Chevron) kind of did a 180 on those two. They're still there, but I hear you, they are in lesser amounts. The ZDDP hasn't seemed to drop that much. I did a CJ4 Delo UOA and it was a tad lower, but not huge. I wonder what the new PC10 formulation will be like?
 
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