Engine Oil

[3500LSCC]

I know everyone has their own, usally STRONG opinions on engine oil. My question is pretty simple. I like and have used mobil 1 for years. I read on the bottle that I can use mobil 1 truck and SUV oil in my Duramax. The only thing is it is 5W-40 when the manual says that the preferred weight is 15W-40. I noticed that the Rotella Synthetic is also 5W-40. Is either of these oils OK to run even though they are 5W instead of 15W. I will be towing a camper in the summer. Thanks

[jbplock]

3500LSCC,

Mobil-1 Truck and SUV is an excellent oil choice for your Duramax - especially for towing (IMHO). It's formulated with Group IV PAO synthetic base stock that has superior high temp properties (good for towing applications). M1 T&SUV is also the same as Mobil Delvac-1 and CAT Synthetic DEO (marketed to large commercial diesels and OTR tractors). The "5" in the 5W40 is an indicator of the low temperature performance and the "40" is the viscosity rating when the oil at operating temp. So, when the 5w40 is hot it is the essentially the same as 15w40. (I've been running Delvac-1 for over 25k miles with good UOA (http://community.webshots.com/photo/65003591/229808739UoqnFU) results).

For more info try a forum search for "Delvac-1"

smile.gif

[jbplock]

Was at my local Wal-Mart today and they are now selling 5-quart jugs of Mobil-1 Truck & SUV for $19.97. http://forum.thedieselpage.com/ubb/icons/icon14.gif I bought two jugs - perfect size for a Dmax oil change :cool:

[OC_DMAX]

I was hoping they were going to come out with at least a gallon jug!! Five quarts per container works out just perfect for a DMAX oil change.

[jbplock]

Looking at the latest datasheets it appears that M1 T&SUV may now be slighly different than Delvac-1 (??) Per the specs, DELVAC-1 is certified for the new API "CI-4 Plus" spec while M1 T&SUV is just "CI-4".

Data Sheets:

DELVAC-1 (http://www.mobil.com/USA-English/Lubes/PDS/GLXXENCVLMOMobil_Delvac_1_5W-40.asp)

Mobil-1 Truck & SUV (http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil_1_Truck_SUV_5W-40.asp)

My 03 manual specifies API CH-4 or CI-4 ... Anyone know if the 04 or 05 manuals refer to the CI-4 Plus spec?

Apparently the CI-4+ spec is designed to handle extra soot produced by the latest EGR equipped engines.

More CI-4+ info:

http://fleetowner.com/equipment/feature/fleet_engine_oils_adding/

http://www.infineum.com/information/api-heavyduty-ci4-2004.html

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[ 04-01-2005, 01:46 AM: Message edited by: jbplock ]

[OC_DMAX]

I don't have an answer to your question, but I wonder if automakers just spec what is currently available. My truck has a soot recycling EGR, yet the 2002 manual specs CH-4 for the oil (CI-4 was not available in 2001 when the manual was printed).

[soot]

Originally posted by jbplock:
Looking at the latest datasheets it appears that M1 T&SUV may now be slighly different than Delvac-1 (??) Per the specs, DELVAC-1 is certified for the new API "CI-4 Plus" spec while M1 T&SUV is just "CI-4".
Maybe Mobil hasn't received the CI-4+ API rating yet for M1 T&SUV, but has for Delvac 1. :confused:

I don't know if Mobil is similar, but Shell's website now states that Rotella T synthetic 5w-40 now meets the CI-4+ rating without needing any reformulating, so it isn't any different than it was before, & it was rated CH-4. I was hoping that the Rotella syn additive package would be updated, similar to what Chevron did to Delo 400 by adding a little Moly, when it received it's CI-4+ rating.

[RdTxTd]

Originally posted by jbplock:
My 03 manual specifies API CH-4 or CI-4 ... Anyone know if the 04 or 05 manuals refer to the CI-4 Plus spec? The 05 manual says...

What Kind of Engine Oil to Use

Look for these two things:

* CI-4 or CH-4

Oils designated as API CI-4 or CH-4 are recommended for your vehicle. The CI-4 or CH-4 designations may appear either alone, together or in combination with other API designations, such as API CI-4/SL.

These letters show American Petroleum Unstitute (API) levels of quality.

Notice: Use only engine oils that have one of these designations CI-4 or CH-4 for the DURAMAX diesel engine. Failure to use the recommended oils can result in engine damage not covered by your warranty.


Dave

[jbplock]

Dave, Thanks for posting the 05 specs.

From reading the articles linked in the earlier post, it seems the CI-4+ is targeted for the newer large commercial Diesels with EGR. The only difference between CI-4 and CI-4+ appears to be an additional Mack T-11 Soot/Viscosity Control Test (The CI-4 just gets the Mack M11-EGR, High Soot Test with EGR). I sent an email to Mobil asking if they have any plans to add the CI-4+ rating and will post their reply. Since the M1 T&SUV is marketed for light trucks and SUVs, maybe they don

[DmaxMaverick]

Good information here.

It should be noted that just because an oil has a later API rating, or a "+", doesn't necessarily mean the oil is any different than the previous rating. All it means is the oil has passed that particular standard. The oil may have been sufficient prior to the test. Unfortunately, the ratings don't specify what engine/manufacturer the rating has been specified for. You have to dig for that info. If it were so critical, the info would be posted on the bottle, or a news release would be made. Don't get me wrong, I feel using the latest rating is a good thing for our Diesel engines. It's just there may be no difference, functionally, between the current rating, and the next. I don't think the API has changed the rating standard for CI-4 rating. Adding a "+" indicates it has passed an additional test within the same standard. It may mean something if you have a specific engine that recommends the "+". If it were a breakthrough, we'd all hear about it.

As it is, I'll continue using the brand I've been using, and trust they will continue to ensure the oil meets the current standards. The oil companies are competitive and don't want to lose business, so they have to keep up with the "Jones's".

[Brian DMT]

I wish I was finding the actual articles to refer to :( , but if memory serves correctly, the new CI-4+ spec was primarily in response to the industry noting instances of abnormally high wear rates in diesel engines in cases where oil soot dispersal additive packages had been depleted. When this occurs, the very small carbon (soot) molecules will rapidly agglomerate to large wear-size particles that are extremely hard and very damaging to bearing and crank surfaces, etc.

To pass the "plus" spec, some oils have to beef up their soot dispersal package. This is a case where it IS wise to be sure the oil you use does pass the CI-4+ requirements.

The other component to this is filtration. Soot particles are very small: sub-micron in size. The more soot particles, the blacker the oil, and the more likely they are to agglomerate to larger sizes. One of the many values of a good bypass filter is to take out the soot - particularly the small agglomerates - before they have a chance to grow to a size where they can cause damage. This is also good because it dramatically reduces the load on the oil's detergent (soot dispersal) package, increasing effective oil life and keeping the engine cleaner. Oil analysis will tell you soot levels.

The bypass filter I use is rated 89% eff. 1st-pass at 1 micron. For comparison, even the best full-flow Duramax filters available (far denser, deeper internal structure than the pleats we're all familiar with) can only be 65% eff at 10 microns! Since wear particle size range is recognized to be 5-20 microns (a range only marginally affected by full-flow filters) it's not hard to imagine the beneficial reduction in engine wear rates from using a bypass filtration system. Your oil actually runs cleaner than many new petroleum oils in their unopened bottles.

[jbplock]

Here's the reply I received from Mobil ...

"From: Mobil Product Information [mobilproducts@ourdataworks.com]
Sent: Monday, April 04, 2005 10:49 AM

Mobil1 Truck and SUV 5W40 and Delvac1 5W40 are slightly different informulation which is considered proprietary. Mobil currently does not have any plans to reformulate the Truck and SUV to meet CI-4 Plus."

[DmaxMaverick]

Greg Landuyt at www.lubespecialist.com (http://www.lubespecialist.com) offers the full range of Amsoil products, including bypass filter additions and oil analysis kits, and is an advertiser here in TDP.