0W40 VS 5W40 for 2006 Jeep Liberty CRD

m0sfet · **Joined:** Thu Apr 21, 2016 10:00 pm **Posts:** 46

The manual says to use 0W40 but most people here use 5W40. What's the reason? Are there any advantages over 0W40 and why? Thanks.

geordi · **Posted:** Sat Aug 06, 2016 9:24 pm

Availability and proper diesel-rated oil, for one.

Below the frost line, you simply cannot purchase a diesel rated 0w-40 unless you have it shipped to you from the frozen North. Any 0w40 that you might find in an auto store (such as Mobil European Car Formula 0w40) is NOT ACCEPTABLE because it is not a diesel rated oil and cannot handle the soot loading.

Just because there is a 0w40 marker on the bottle, that only refers to the viscosity, but you have to look at the circle symbol on the back of the bottle to see the real rating. The API Service Grade symbol will have a letter code, something like Sx (usually SN right now) for spark ignition engines, where SN is a higher rating than SM. Diesel rated oil will usually be CH or higher, right now I think most are up to CJ-4 which is the 4th revision of CJ.

Our CRDs require at least a CF rating, anything higher than that is acceptable. Bear in mind that a 0w base oil has to be thinner and have more friction modifiers to reach 40 weight after warming up above 32 degrees, than a 5w or a 15w. Those friction modifiers can be consumed over the life of the oil change, and many CRD owners are starting to have the opinion that the factory 6500 mile change intervals are WAY too long.

First problem is that the "severe service" chart is not well explained. Those criteria (lots of starts and stops, city driving, hot conditions, dusty conditions, off road conditions, towing, high speed driving) are not based on "you must do all of these to be severe service" it is more like "if you do ANY OF THEM then you are severe service". The only people that should be running to 6500 miles are the Suzy-Soccermom types that never exceed 2000 rpm and 50mph, but have at least a 15 minute drive every time they turn the engine on.

Everyone else should be changing their oil between 3000 and 5000 miles, depending on the severity of your conditions.

flash7210 · **Posted:** Sat Aug 06, 2016 9:31 pm

Delo 400 LE 5w-40
Shell Rotella T6 5w-40
Mobil 1 turbo diesel truck 5w-40

All the above are made specifically for turbo diesel engines and are available at walmart.

geordi · **Posted:** Sat Aug 06, 2016 9:54 pm

flash7210 wrote:

Delo 400 LE 5w-40
Shell Rotella T6 5w-40
Mobil 1 turbo diesel truck 5w-40

All the above are made specifically for turbo diesel engines and are available at walmart.

Yeah - Use any of those interchangeably... I forgot to mention specific brands in my post where I got sidetracked by the thought of not changing it often enough. I've seen the results of lack of oil changes, and it isn't pretty. But using the wrong stuff can also play havoc with the engine too.

The oiling passages are TINY, and (get this) the wrist pins of the piston and the underside of the piston are cooled and oiled by a directed jet of oil into a hole in the underside of the piston! If that sprayer isn't aimed right or is junked up... Bye bye piston.

WWDiesel · **Posted:** Sun Aug 07, 2016 2:16 pm

If you use Rotella oil in your diesel engine, Heads up on coming changes to their CJ-4 rated oils!
Shared from a friend who sent me this:
If any of you use Shell's Rotella T5/T6 CJ4 diesel oil, Shell announced that beginning August 1, this year, (6 days ago), they're replacing CJ4 with 2 different oils, to help meet the EPAs newer 2017 stricter diesel emissions. For the first time, they're splitting the oil into 2 categories:

• CK4 - heavy HTHS, up to 4.2 (40W) for heavy duty and off-road diesel's - backward compatible with CJ4 and earlier oil requirement
• FA4 - newer, low HTHS (3.5 in 30 weight), thin viscosity for stricter emissions and fuel economy requirements

For those of you who may want to buy some extra CJ4 oil while it's still available, heads up as it will disappear just as CI4+ did some years ago, at lease for Shell oil. When CJ4 oil first came out, there were some issues with wear protection, it was tweaked over time as BITOG VOA's showed over a 2 year period. It's possible the same issue happens again. Maybe not, who knows?

More information can be otained from Rotella's web site at:
http://rotella.shell.com/rotella-products/pc-11.html

disclaimer: I do not use Rotella oil but figured anyone using it would want to know of the upcoming changes.... :wink:

geordi · **Posted:** Sun Aug 07, 2016 2:33 pm

Thanks for that, I had no idea - I would stay with the heavier option anyway, it sounds like the lighter one won't be a 40 weight which is what we need.

But maybe I will just stick with Mobil 1 TDT or Delvac 1 (sold at truck stops) instead for a while. I've never personally used the Delo products so I can't speak to their performance.

WWDiesel · **Posted:** Sun Aug 07, 2016 3:18 pm

If you read what they are saying, due to the tyrannical hypocrisy EPA, they are making these changes! :furious:

Rotella wrote:

As PC-11 engine oils get closer to arriving, you may hear the term High Temperature High Shear (HTHS) viscosity. CK4 oils are being referred to inside the industry as “High HTHS” engine oils, and FA-4 oils are being referred to as “Low HTHS” oils. These Low HTHS FA-4 oils are being designed to provide fuel economy above and beyond current CJ-4 and FA-4 oils through the use of thinner viscosity fluids.

No doubt, not good for older diesel engines already running on the viscosity edge!!!! :grim:

Be careful what you pour into your motor!

m0sfet · **Joined:** Thu Apr 21, 2016 10:00 pm **Posts:** 46

So as long as the bottle says 5W40 (on new bottle), it should be good for my CRD, right?

geordi · **Posted:** Sun Aug 07, 2016 4:47 pm

m0sfet wrote:

So as long as the bottle says 5W40 (on new bottle), it should be good for my CRD, right?

AND the API service symbol on the back is at least a "CF" grade or better. CH is better than CF, etcetera as I posted above.

There are many gas-only 5w-40 oils that would NOT be acceptable at all for your CRD.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

I am surprised to see that the every Liqui Moly Diesel oil is rated only " CF " . I use the Diesel High Tech 5W-40 right now :oops:

I wonder if there is something to do with the fact that this oil is from Europe and the API certification is a U.S.......... maybe the recent API certification have more to do with with emission and DPF and EGR compatible oil than anything else.
Since our little engine is from Europe and we're mostly not using EGR and we don't have DPF we probably don't need the latest API certification or maybe we should look at ACEA ( European Automobile Manufacturers Association ) rating ????

Sir Sam · **Posted:** Sun Aug 07, 2016 7:09 pm

Delo 15-40 CJ-4 for 120k miles meant ZERO bearing play at 155k on the rockers(along with EHM, ORM).

Go thicker.

m0sfet · **Joined:** Thu Apr 21, 2016 10:00 pm **Posts:** 46

I think I'll just use mobil 1 0W40 as that's always available at Walmart here.

Sir Sam · **Posted:** Sun Aug 07, 2016 7:25 pm

m0sfet wrote:

I think I'll just use mobil 1 0W40 as that's always available at Walmart here.

Ugh.

Ok. Do you have the time and ability to replace the rockers when they fail?

Also Walmart carries the dell mentioned above. Also carries motor craft diesel oil. Both are better alternatives to the 0-40 mobile.

geordi · **Posted:** Sun Aug 07, 2016 8:06 pm

m0sfet wrote:

I think I'll just use mobil 1 0W40 as that's always available at Walmart here.

I have seen the results (as has Sir Sam) of using oil that is too thin or is not diesel rated.

90% of the USA DOES NOT HAVE ACCESS to a diesel rated 0w-40, so I am very confident in my belief that whatever 0w40 you would be able to source from Wal-Mart... Unless you are in International Falls or North Dakota... The likelihood is that it will not be an acceptable oil.

The problem is that the soot will clog the oil very rapidly, and the lack of thickness in the oil coating will allow metal-on-metal contact when the heat causes the oil to shear itself and run right off the surfaces. This will cause the rocker bearings to wear very quickly, and can cause the bottom end crankshaft and rod bearings (which are just flat pieces of steel with ONLY an oil cushion as the "bearing" to protect them) to have no protection at all - and they will overheat and melt away.

I'm the traveling mechanic for these engines. I help people with these things, but I hate finding one that has been abused with the wrong oil or lack of maintenance. The results are NEVER pretty or cheap.

undrgnd · **Joined:** Sat Mar 26, 2016 4:47 am **Posts:** 194

Sir Sam wrote:

Delo 15-40 CJ-4 for 120k miles meant ZERO bearing play at 155k on the rockers(along with EHM, ORM).

Go thicker.

Sir Sam, is this a synthetic oil? Down here in NZ, this is a multi grade oil. I thought ours needed to be synthetic??

Sir Sam · **Posted:** Mon Aug 08, 2016 12:09 am

undrgnd wrote:

Sir Sam wrote:

Delo 15-40 CJ-4 for 120k miles meant ZERO bearing play at 155k on the rockers(along with EHM, ORM).

Go thicker.

Sir Sam, is this a synthetic oil?

I believe they have both synthetic and conventional in the delo line both rated for cj-4.

However most of the Delo I have used over the years has been conventional.

racertracer · **Posted:** Mon Aug 08, 2016 12:55 am

Sam,

I use 15w-40 conventional also at 3200 mile intervals.

What are your oil change intervals?

tcoilburner · **Posted:** Mon Aug 08, 2016 9:25 am

I have used Mobil 1 0w40 for 162,000 miles no trouble. When I had to do the head gasket last year, the inside of the motor is very clean. No rocker arm trouble, I sure because of the GDE tune. Our engine is a euro built motor and Mobil 1 is a Euro diesel specific oil , ACEA A3 rating. Use what ever oil you wish, but you are fine using this.

racertracer · **Posted:** Mon Aug 08, 2016 9:38 am

tcoilburner wrote:

I have used Mobil 1 0w40 for 162,000 miles no trouble. When I had to do the head gasket last year, the inside of the motor is very clean. No rocker arm trouble, I sure because of the GDE tune. Our engine is a euro built motor and Mobil 1 is a Euro diesel specific oil , ACEA A3 rating. Use what ever oil you wish, but you are fine using this.

What are your oil change intervals?

tcoilburner · **Posted:** Mon Aug 08, 2016 10:04 am

9000 miles. The oil does not get very dark colored, until about 6000 miles. Yet, you can see your finger through the oil still.

0W40 VS 5W40 for 2006 Jeep Liberty CRD

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