I am not interested in any responses about why would I want to pay more for Amsoil etc. I have already made up my mind to give the product a try and am only interested in some advice as to the weight and proper product selection.

I see that Amsoil has the following 3 oils recommended for the CRD:

5W40 Premium Diesel Oil
10W40 Synthetic High Performance
Series 3000 Synthetic 5W30 HD


The CRD manual specifies either 0W40 or 5W40. I just purchased some of the 5W40 from Amsoil but am wondering if that is a mistake. I see that the TBN is a lot lower than the 5W30 Series 3000 and the TBN is even less than the Mobil-1 0W40 that I have been using. I also see that Amsoil recommends their 5W40 for 2007 and newer engines.

So, I have purchased an oil change worth of the 5W40 for this time but I am interested in knowing if I should switch to the 5W30 HD oil for my next change?

I have ~25K miles on it and roughly 40% of my miles are spent towing a 3,000LB trailer.

Thanks in advance.

---Aaron

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2006 Jeep Liberty CRD, Black

The DEO 5w40 is a CJ-4 oil that was a development for the '07 engines that had particulate traps in the exhaust stream. It is backward compatible, so it is fine to use in the CRD.

True, most CJ-4 oils have a lower TBN than previous specs. If this is a concern, then you could easily use the AMO 10w40 offering by Amsoil. It works fine in the CRD as well. I currently use it. It has a >12 TBN.

I have done a few UOA's on the DEO 5w40 when I was using it. There was not a significant drop in TBN if you are changing in the 6K-8K mile range. If you are going for extended drains and doing UOA's, then going to the AMO 10w40 would be a good choice. Else, you didn't do anything "bad" by going with the DEO 5w40.

Relax.... all is well.

The HDD 5w30 will work also. It is a CI-4+ oil. I have seen a few semi diesels running it with no problems. It is a bit pricey, so unless you are doing the extended drain/UOA thing, you would save more by sticking with the 5w40 or 10w40.

Don't get to excited about the first number in an oil spec, be it a 0w, 5W, or 10w. These are the winter flow ratings and even the 10w40 AMO Amsoil will flow well down to -40F. By then, most will have the block heater plugged in or have installed an oil pan heater pad, so all of this is academic anyway. When the engine is running and up to operating temps, you could have a 20w50 oil in -70F conditions doing just fine. We used a 15w40 for years in Alaska with no problems. Just plugged everything in when shutting down and the oil flowed with no problems and did it's thing quite well down to -72F (coldest I was in).

Oil brands are another thing, but it is safe to say that all the major brands of synthetics are fine to use in the CRD. I prefer Amsoil, but don't get too excited if someone disagrees.

Relax... take a breath and enjoy the CRD!

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Environmentalist Green + Socialist Red = Facist Brown

2006 Liberty CRD, Frankenlift II, Al's A Arms, Moog LBJ's, GDE tune, Etechno GX3123 Glow plugs, Fumoto drain valve, Elephant hose CCV mod.

Cowpie1,

Thanks for your response. I am relaxed...I just was concerned my question would turn into a Amsoil vs non Amsoil pissing contest and I want to avoid that as it seems to be very non-productive in all the threads I reviewed.

You stated not to be concerned about the 1st number and I now understand that. Thanks. What about the second number? Will there be a big difference between the 5w30 and 5w40 in engine protection and/or mileage?

---Aaron

_________________
2006 Jeep Liberty CRD, Black

The AME 15W-40 gave me the best UOA reports...better than the others

http://www.amsoil.com/StoreFront/ame.aspx

_________________
Founder of L.O.S.T.
2006 CRD Sport
Mods: GDE Hot Tune w/ 364#@2000rpm/Air Box /3" Str8 Exhaust/ASFIR Alum Skids/245-75R-16 Cooper STT PRO/OME LIFT w/Clevis & 4 Spring Isos/AirTabs/Rigid 10" S2 LED/4xGuard Ctr Matrix Bumper
Drag Strip:Reac=.1078_60ft=2.224_1/8=10.39@64.8mph_1/4+16.46@80.8mph