Rotella: The world's first ever combined hair oil, foot ointment, and salad dressing
CF Veteran

Joined: Nov 2015
Posts: 3,636
Likes: 469
From: Southern OH
Year: 1997
Model: Cherokee(XJ)
Engine: 4.0
I never use synthetic oils, I think regular 15w40 diesel oil offers plenty of protection and I change it at least every 5K. People use synthetic because it doesn't break down as quick which is true but it still gets dirty just like regular oil does. I would rather have good clean oil that I change every 4-5K then run a synthetic and change at 8-10K.
I never use synthetic oils, I think regular 15w40 diesel oil offers plenty of protection and I change it at least every 5K. People use synthetic because it doesn't break down as quick which is true but it still gets dirty just like regular oil does. I would rather have good clean oil that I change every 4-5K then run a synthetic and change at 8-10K.
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
Stating that everyone should change their oil every 4-5K miles is over generalizing things, IMO. Examine some some oil analysis comparisons. Two identical engines can contaminate or wear oil additives very differently, and therefore have different OCI requirements. Likewise, the characteristics of the oil base and additives can affect OCI requirements as well.
Stating that everyone should change their oil every 4-5K miles is over generalizing things, IMO. Examine some some oil analysis comparisons. Two identical engines can contaminate or wear oil additives very differently, and therefore have different OCI requirements. Likewise, the characteristics of the oil base and additives can affect OCI requirements as well.
They are a bandaid to try and make us feel better but it's not going to cure the cut. Only a thorough rinsing will prevent infection.
Last edited by Bugout4x4; Oct 15, 2017 at 10:10 AM.
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
There are many other reasons to change oil than particles in suspension. And again, all engines will collect particulate matter, combustion gasses, fuel dilultion, etc. at differing rates. Oil analysis will lead you to a more fact-based determination of oil change interval, rather than making the assumption that all engines have too many particulates in suspension, too much acid, fuel dilution, etc. past 5K miles and therefore a 4-5K mile OCI is necessary for everyone.
Last edited by Tbone289; Oct 15, 2017 at 11:17 AM.
Senior Member
Joined: Jun 2014
Posts: 925
Likes: 6
From: Eagle River, Alaska
Year: 1999
Model: Cherokee (XJ)
Junior Member
Joined: Aug 2016
Posts: 44
Likes: 1
From: Washington
Year: 2000
Model: Cherokee
Engine: 4.0L AMC-242 I6
That chart may also be due for an update, Salad, if you're reading this.
I know Chevron's gotten rid of their 15-40 LE oil and replaced it
with something else like 15-40 XLE or SDE. I hear the Ford guys
don't like it too much.
Not sure if Shell's switched it up either.
I know Chevron's gotten rid of their 15-40 LE oil and replaced it
with something else like 15-40 XLE or SDE. I hear the Ford guys
don't like it too much.
Not sure if Shell's switched it up either.
Senior Member
Joined: Sep 2014
Posts: 580
Likes: 0
From: Saginaw Mi area
Year: 1994
Model: Cherokee
Engine: 4.0
I hear & see a lot about brands of oil filters on various forums. Some folks get carried away about oil filters, as well as which brand of spark plugs are the "best", which oil is the "best" which brand of beer..
.. etc...
I would bet that most people talking about oil filters, don't own a filter cutter, to actually see what has collected in it's media...
( if it looks like aluminum paint, you are in big trouble !)
I figure that any brand of filter is better than the old days, where full-flow filters hadn't arrived yet. Chevy, in 1956, and Cadillac, not until 1960 !! They had the by-pass type though, mounted on the top of the engines, which sorta helped...
Happy Thanksgiving folks !!
I would bet that most people talking about oil filters, don't own a filter cutter, to actually see what has collected in it's media...
( if it looks like aluminum paint, you are in big trouble !)
I figure that any brand of filter is better than the old days, where full-flow filters hadn't arrived yet. Chevy, in 1956, and Cadillac, not until 1960 !! They had the by-pass type though, mounted on the top of the engines, which sorta helped...
Happy Thanksgiving folks !!
CF Veteran

Joined: Nov 2015
Posts: 3,636
Likes: 469
From: Southern OH
Year: 1997
Model: Cherokee(XJ)
Engine: 4.0
All of the Diesel motor oils have switched from CJ-4 to CK-4 spec. Ford Originally rejected the use of CK-4 oils in the 6.7 Powerstroke and put out a list of approved oils, but all of that has pretty much been settled now. Every other diesel engine manufacturer has approved the new CK-4 spec oil. Not much has changed between the old CJ-4 and CK-4 spec and they still offer much better protection then gas engine oils do in my opinion, so I will continue to run 15w40 diesel oil in all of my engines.
Junior Member
Joined: Sep 2013
Posts: 69
Likes: 0
From: Picture Rocks & Vernon AZ
Year: 1987
Model: Cherokee
Engine: 4.0
All of the Diesel motor oils have switched from CJ-4 to CK-4 spec. Ford Originally rejected the use of CK-4 oils in the 6.7 Powerstroke and put out a list of approved oils, but all of that has pretty much been settled now. Every other diesel engine manufacturer has approved the new CK-4 spec oil. Not much has changed between the old CJ-4 and CK-4 spec and they still offer much better protection then gas engine oils do in my opinion, so I will continue to run 15w40 diesel oil in all of my engines.





